JPH0662494A - Speaker oscillation system supporting body and speaker - Google Patents

Abstract

PURPOSE:To provide a supporting body whose various characteristics such as the internal loss are improved by using a base fabric, which is made of whole aromatic polyester fibers having specific repeat units, as a principal constituent. CONSTITUTION:While whole aromatic polyester fibers having repeat units expressed by formulas I and II are impregnated with thermosetting resin and are unified to obtain the base fabric, and this base fabric is used as the principal constituent to form an oscillation systems supporting body for speaker. Thus, the oscillation system supporting body for speaker is obtained which has a high molding workability and accurately reproduces prescribed ruggedness, depth, etc., and has a large internal loss to sufficiently attenuate the oscillation propagation and has superior elastic supportability and damping action and has a low water absorption rate with dimensions less changed and has the specific acoustic characteristic and the durability enhanced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibration system support of a speaker and a speaker provided with the support. More particularly, the present invention relates to a speaker vibration system support that can provide a speaker having excellent moldability and excellent acoustic characteristics.

[0002]

2. Description of the Related Art A support such as a damper or an edge of a speaker that supports a speaker diaphragm maintains the posture of the diaphragm driven by a voice coil in order to improve the acoustic characteristics of the speaker. Is required, no abnormal vibration such as resonance is generated, and a large internal loss capable of sufficiently damping the propagation of vibration is required.

Conventionally, in order to solve such a problem, the damper is a woven cloth of natural fibers or synthetic fibers impregnated with a thermosetting resin and heat-molded, or a butterfly damper formed of metal foil. There are things that are known. In addition, as the edge material, as is the case with fixed cones, paper is molded and coated with a dumping agent.For free edge cones, woven or non-woven fabrics of natural or synthetic fibers are coated with thermosetting resin. Also impregnated or coated,
Further, a material coated with a thermoplastic resin, a material formed by laminating a thermoplastic elastomer, or the like has been used.

However, conventional paper, natural fiber, synthetic fiber base cloth impregnated with a thermosetting resin, or molded metal foil has a high resonance point or a small internal loss. There was a problem that it was inferior in vibration damping property and that the acoustic characteristics were never high. In particular, dampers are generally made by impregnating cotton cloth with phenolic resin and molding this.However, because the brittleness of phenolic resin cannot be covered with cotton cloth, the deviation changes due to long-term vibration. There is also the problem of coming. Further, when paper is used as a material, there are drawbacks such that the amplitude cannot be made large, and paper and natural fiber have a large moisture absorption and are easily affected by humidity. Many of these materials and synthetic fibers are flammable and are not particularly suitable as a member for a speaker near the power supply of a television.

After forming a base cloth layer by impregnating a paper, natural fiber or synthetic fiber base cloth with a thermosetting resin, it is formed into a circular corrugated shape by vacuum forming, pressure forming or press forming, and is then trimmed into edges and dampers. Since it is used as a support for etc., it is important for the acoustic characteristics to be accurately shaped into a predetermined shape and size, and it is important to maintain this during use. There is a problem in that the vibration causes a decrease in rigidity of the damper and the edge, and the displacement changes in the case of the damper and the minimum resonance frequency changes in the case of the edge, and improvement of this point has been particularly desired.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to have excellent moldability, to be able to accurately reveal a predetermined uneven shape and depth, and to sufficiently damp vibration propagation. It has a large internal loss that can be achieved, and also has a good elastic support and damping function required for a speaker vibration system support, low water absorption rate, small dimensional change, and excellent acoustic characteristics and durability. Another object of the present invention is to provide a support for a speaker vibration system such as a speaker diaphragm.

[0007]

As a result of continuous research by the present inventors, a base fabric made of wholly aromatic polyester fiber was used as a main structural material constituting a support of a speaker vibration system, and a thermosetting resin was used for the base fabric. The present invention has been completed by finding that the above problems can be solved by forming a support for a speaker vibration system by impregnating and integrating a resin.

[0008] That is, the present invention is a vibration system support for a speaker, which comprises a base fabric made of wholly aromatic polyester fibers impregnated with a thermosetting resin and integrated as a main structural material.

In the present invention, the base fabric, which is the main structural material of the support, is formed from wholly aromatic polyester fiber,
The "whole aromatic polyester" referred to here has a repeating unit mainly composed of an aromatic dicarboxylic acid component and an aromatic diol component, or has a repeating unit composed of an aromatic hydroxycarboxylic acid component. The wholly aromatic polyester may optionally have small amounts (usually 20 mol% or less) of other repeating units.

Typical examples of the repeating units constituting the wholly aromatic polyester include the units represented by the following formulas (I) to (YII).

[0011]

[Chemical 3]

[0012]

[Chemical 4]

[0013]

[Chemical 5]

[0014]

[Chemical 6]

[0015]

[Chemical 7]

[0016]

[Chemical 8]

[0017]

[Chemical 9]

However, it is not limited to the repeating units of the above formulas (I) to (VII), and other aromatic dicarboxylic acid units, aromatic diol units and / or aromatic hydroxycarboxylic acid units are included. You can leave.

The most typical wholly aromatic polyesters suitable for use in the support of the present invention include those of formula (I) above.
Mention may be made of wholly aromatic polyesters which consist primarily of repeating units of the formula (II). In that case, from the viewpoints of rigidity, thermal characteristics, the amount of internal loss, etc. of the resulting support, 50 mol% or more of the wholly aromatic polyester is composed of repeating units of the formula (I). It is preferred to include less recurring units of formula (II), and optionally small amounts of other aromatic ester units, especially recurring units of formula (I): recurring units of formula (II) , 60: 40 ~
A wholly aromatic polyester in a molar ratio of 90:10 is preferred.

The wholly aromatic polyester fiber can be produced by melt spinning the above-mentioned wholly aromatic polyester, and a typical example of such wholly aromatic polyester fiber is manufactured by Kuraray Co., Ltd. "Vectran fiber" (trade name) can be mentioned.

As the base fabric made of wholly aromatic polyester fiber, a woven fabric made of filament yarn of wholly aromatic polyester fiber, a woven fabric made of spun yarn, and a nonwoven fabric made of short fibers are suitable. Among these base fabrics, a woven fabric made of spun yarn of wholly aromatic polyester fiber is more preferable because it can give good acoustic characteristics to the speaker.

The basis weight of the base fabric made of wholly aromatic polyester fiber is preferably 30 to 300 g / m ² ,
50 to 250 g / m ² is more preferable. If the basis weight of the base cloth is less than 30 g / m ² , the rigidity of the speaker vibration system support itself, such as the edges and dampers obtained by impregnating and integrating the base material with the thermosetting resin, becomes poor and the shape retention is poor. As a result, it becomes difficult to function as a support. On the other hand, the basis weight of the base fabric is 300 g / m
^When it exceeds ² , the shapeability is poor, the shape stability itself is poor, and the rigidity is too high, abnormal vibration is likely to occur, and the acoustic characteristics are easily deteriorated. The base fabric made of the wholly aromatic polyester fibers as described above can be produced by a conventional method using filament yarns, spun yarns and short fibers made of the wholly aromatic polyester fibers.

In the present invention, the base fabric made of wholly aromatic polyester fibers is impregnated with a thermosetting resin to be integrated. As the thermosetting resin, phenol resin, urea resin, epoxy resin, unsaturated polyester resin, thermosetting polyurethane or the like can be used.

The speaker vibration system support of the present invention is obtained by uniformly impregnating a base fabric made of wholly aromatic polyester fiber with a thermosetting resin precursor in a liquid, solution, melt or powder state before curing. Or by uniformly spraying and then molding by vacuum molding, pressure molding, press molding, etc. and at the same time heat-curing the resin to impregnate and integrate the thermosetting resin into the base cloth, for example, concentric concavo-convex Supports having shapes and other shapes can be formed.

As the resin to be impregnated and integrated with the base cloth, a thermosetting resin is used from the viewpoints of morphological stability of the support obtained from it, reproducibility of irregularities during molding, heat resistance, flame retardancy and the like. It is necessary to be present, and a phenol resin is particularly preferable in terms of handleability, flame retardancy, processability, cost and the like.

As the phenol resin, any of phenol resins obtained from phenols such as phenol, cresol, xylenol, resorcin and aldehydes such as formaldehyde, acetaldehyde, furfural and the like can be used. Both resins and novolac type phenolic resins can be used. Among them, the resol type phenol resin is preferable.

The thermosetting resin is preferably impregnated in a proportion of about 3 to 50% by weight, based on the fiber weight of the base fabric, and particularly preferably 5 to 30% by weight. When the amount of the thermosetting resin impregnated is less than 3% by weight, the shapeability of the base fabric impregnated with the thermosetting resin becomes poor and the shape retention of the resulting support is lowered. On the other hand, when the amount of the thermosetting resin impregnated exceeds 50% by weight, the rigidity of the obtained support becomes too large, and the elastic support function of the support is lowered, resulting in poor acoustic characteristics of the speaker.

In obtaining the support of the present invention, as described above, the thermosetting resin or its precursor is liquid, powder, solution, molten or film-like on the base fabric made of wholly aromatic polyester fiber. After impregnating, spraying or stacking in the form of a sheet, vacuum forming, pressure forming, press forming, etc. are performed to uniformly impregnate the thermosetting resin into the base fabric and integrate it. At the same time, a method of forming into a concentric concavo-convex corrugated shape or another shape can be adopted depending on the structure and shape of each speaker, the type of support, and the like.

However, in the present invention, the method for manufacturing the support and the method for forming the support are not particularly limited to the above-mentioned methods, and a base fabric made of wholly aromatic polyester fibers impregnated with a thermosetting resin and integrated is a main structural material. Any of the speaker vibration system supports described above are included in the present invention. Furthermore, the support of the present invention may be provided with other members and materials as needed, in addition to the base fabric made of wholly aromatic polyester fibers impregnated with and integrated with the thermosetting resin. For example, a film or sheet made of polyurethane or other synthetic resin or rubber, a synthetic resin or rubber foam sheet, or a metal foil is laminated on a base fabric made of wholly aromatic polyester fiber impregnated with thermosetting resin. May be subjected to a molding process to form the support of the present invention having a laminated structure whose main constituent is a base fabric made of wholly aromatic polyester fibers impregnated with a thermosetting resin.

The support of the present invention is used as a speaker edge or a damper for supporting a vibration system such as a speaker diaphragm. The type, structure, shape and the like of the speaker and the vibration system to which the support of the present invention is attached are not particularly limited, and the support of the present invention can be used for any vibration system of the speaker.

[0031]

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited thereto.

Example 1 (1) A wholly aromatic polyester fiber having a repeating unit represented by the above formula (I) and a repeating unit represented by the formula (II) in a molar ratio of 3: 1 [( Made by Kuraray Co., Ltd .; Vectran] A plain weave woven fabric (a basis weight of 123 g /
m ² ) was used as the base fabric. The base cloth was uniformly impregnated with 20% by weight of a phenol resin, dried at 100 ° C. for 10 minutes, and made into a barely usable state (B stage state) at room temperature.

(2) The B-stage phenolic resin-impregnated base fabric formed as described above is sandwiched between upper and lower molds having concentric circular corrugations, and the temperature is 240 ° C. and the pressure is 4 kg / c.
Press molding was carried out for 7 seconds under the condition of m ² to prepare a damper material 1 having concentric corrugated irregularities 2 shown in FIG. The inner peripheral side 3 and the outer peripheral side 4 of the damper material, which had no unevenness, were cut and removed to prepare a damper 5 for a speaker shown in FIG.

(3) 60 g of urethane resin on the B-stage phenol resin impregnated base fabric produced in (1) above.
After coating with a coating amount of / m ² , it is sandwiched between upper and lower molds having concentric circular wavy irregularities, and the temperature is 240 ° C.
Press-mold for 7 seconds under a pressure of 4 kg / cm ² ,
A material for edges having concentric corrugated concavities and convexities similar to FIG. 2 was produced. An edge for a speaker was produced by cutting and removing the inner peripheral side and the outer peripheral side of the edge material, which had no unevenness.

(4) In the press molding of the above-mentioned damper and edge, since the woven cloth using the spun yarn of wholly aromatic polyester fiber is the main constituent material, the woven cloth has appropriate rigidity and strength. From the above, it is very good to follow the mold along the mold, and the corrugated uneven shape can be accurately applied to the support such as the damper and the edge. As a result, the damper and the edge obtained in this Example 1 are: It had an exact predetermined shape and size. Also,
The water absorption, internal loss and oxygen index of the damper and the edge obtained in Example 1 were measured by the following methods, and the results shown in Table 1 below were obtained.

<Comparative Example 1> A plain weave woven fabric (weight per unit weight: 120 g /
A damper for a speaker and an edge were produced in the same manner as in Example 1 except that m ² ) was used as the base fabric. The water absorption of the damper and the edge obtained in Comparative Example 1,
The internal loss and oxygen index were measured by the following methods, and the results shown in Table 1 below were obtained.

Method of measuring water absorption of damper and edge :
After cutting into a test piece of a suitable size from the damper and the edge obtained in the examples or comparative examples, the weight is accurately weighed. Next, the test piece was allowed to stand in an atmosphere of 45 ° C. and 95 RH% for 96 hours, then its weight was accurately weighed again, and the moisture absorption rate was determined from the weight difference before and after standing.

Measurement of internal loss of damper and edge
Method : A test piece having a width of 3 mm and a length of 70 mm was cut out from the damper and the flat portion at the edge of the edge obtained in Examples or Comparative Examples, and a dynamic viscoelasticity measuring apparatus (manufactured by Orientec Co .; Rheovibron DDV-III) was used. ) Was used to measure the internal loss in the tensile deformation mode under the condition of the measurement frequency of 100 Hz.

Measurement of damper and edge oxygen index
Method : Measured according to the combustion test method for polymer materials according to the acidity index method of JIS K-7201-1976.

[0040]

[Table 1]

A moisture resistance test was conducted using the dampers obtained in Example 1 and Comparative Example 1. When the outer peripheral edge of the damper is gripped and the lower end of the cylindrical load of 50g weighted in the circumferential direction is in contact with the inner peripheral edge of the damper, the mark position is set to 0, and then a load of 50g is applied. The position of the marked line was read and the amount of change (referred to as deviation) was calculated and used as the deviation before the test. Next, at a load of 50g, 45 ℃, 95R
After standing in an atmosphere of H% for 96 hours, the position of the marked line was read and the amount of change was used as the deviation after the test. The results of the moisture resistance test are shown in Table 2 below.

[0042]

[Table 2]

From the results shown in Tables 1 and 2 above, the damper and the edge of Example 1 of the present invention, which uses the base fabric made of wholly aromatic polyester fiber as a main constituent, uses the fabric made of cotton yarn. Compared to the damper and the edge of Comparative Example 1, the water absorption rate is extremely small, and dimensional change and deviation do not occur over time, and further, internal loss is large and vibration propagation can be sufficiently dampened. It is understood that is large and flame retardant.

Example 2 and Comparative Example 2 Using the dampers of Example 1 and Comparative Example 1, the magnetic circuit parts shown in FIG. 3 were assembled and a vibration test was conducted. As the test conditions, a 25-pole voice coil had a DCR of 4 ohms and an amplitude of ± 5 mm, and the test was conducted for 1000 hours. The displacement amount of the damper before and after the test was measured, and the results shown in Table 3 below were obtained.

[0045]

[Table 3]

From the results shown in Table 3 above, it can be seen that the one using the base fabric made of wholly aromatic polyester fiber has a high ability to retain the shape and has a small change with respect to humidity and vibration for a long time.

Example 3 A speaker having the structure shown in FIG. 4 was assembled using the damper and the edge manufactured in Example 1. FIG. 4 is a vertical cross-sectional view of the speaker. In the figure, 5 is a damper, 6 is an edge, and 7 is a magnet. The upper plate 8, the lower plate 9 and the center pole 10 form a magnetic circuit. There is. Also, 1
Reference numeral 1 denotes a diaphragm, 12 denotes a voice coil, and the damper 5 of the present invention manufactured in (2) of Example 1 on the upper plate 8.
However, the edge 6 of the present invention produced in (3) of Example 1 is further provided on the frame 13. The result of measuring the frequency sound pressure of this speaker is shown in B of FIG.

Comparative Example 3 Using the damper and the edge manufactured in Comparative Example 1, a speaker having the structure shown in FIG. 4 was assembled in exactly the same manner as in Example 3. The result of measuring the frequency sound pressure of this speaker is shown in A of FIG.

According to the results of Example 3 and Comparative Example 3, the frequency sound pressure curve of the speaker using the conventional cotton cloth and the speaker using the edge has a large irregularity, whereas the cloth using the basic cloth of the wholly aromatic polyester fiber. It can be seen that the frequency sound pressure curve of the speaker using the damper and the edge has smooth acoustic characteristics that the unevenness is not suppressed due to the large internal loss of the wholly aromatic polyester fiber, and that it has excellent acoustic characteristics.

[0050]

The speaker vibration system support of the present invention comprises:
It has excellent moldability, can accurately reveal a predetermined uneven shape and depth, and has a large internal loss that can sufficiently attenuate the propagation of vibration. Further, it has a good elastic supporting action and vibration damping action required for a support of a speaker vibration system, and has a low water absorption rate and a small dimensional change, so that it is possible to provide a speaker excellent in acoustic characteristics and durability. it can. Furthermore, by using flame-retardant wholly aromatic polyester fiber as the main constituent material,
It has the high flame retardancy required for electrical equipment in recent years and is excellent in disaster prevention.

[Brief description of drawings]

FIG. 1 is a view showing a shape of a damper material obtained by press molding in Example 1 and Comparative Example 1.

FIG. 2 is a diagram showing a shape of a damper obtained from the damper material shown in FIG.

FIG. 3 is a schematic diagram of a vibration test performed by mounting the damper manufactured in Example 1 or Comparative Example 1.

FIG. 4 is a vertical cross-sectional view showing the structure of the speaker of Example 3 or Comparative Example 3 assembled by attaching the damper and the edge manufactured in Example 1 or Comparative Example 1.

5 is a frequency sound pressure curve obtained in Example 3 and Comparative Example 3. FIG.

[Explanation of symbols]

 1 Material for damper 2 Concentric concavo-convex shape 3 Inner side without unevenness of material for damper 4 Outer side without unevenness of material for damper 5 Damper 6 Edge 7 Magnet 8 Upper plate 9 Lower plate 10 Center pole 11 Vibration plate 12 Voice Coil 13 frame

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Claims (4)

[Claims] 1. A vibrating support for a speaker, which comprises a base fabric made of wholly aromatic polyester fibers impregnated with a thermosetting resin and integrated as a main structural material. 2. The vibration system support for a speaker according to claim 1, wherein the base fabric is a woven fabric made of spun yarn of wholly aromatic polyester fiber. 3. The wholly aromatic polyester fiber has the following formula:
(I); And the following formula (II); The vibration system support of the speaker according to claim 1 or 2, which is a wholly aromatic polyester fiber mainly composed of a repeating unit represented by: 4. A speaker, comprising the vibration system support of the speaker according to claim 1.