JP3879627B2 - Speaker diaphragm and speaker using the same - Google Patents

Description

【００６６】
（表１）より、実施例１および実施例２は比較例１に比べて、低ｆ０化、低歪化が実現できていることがわかる。
【００６７】
これらのスピーカ用振動板は、その材質や材厚は、形状安定性やコストの点で望ましく、マイクロスピーカに要求される内部損失、材厚、重量を満足させることができる。
【００６８】
前記の構成とすることで、携帯電話に代表されるマイクロスピーカや一般のスピーカに要求される性能を満足できるスピーカを提供することができる。
【００６９】
【発明の効果】
以上のように本発明は、樹脂製基材の表、裏面または片面にエラストマー層を設けて複層構造を有するスピーカ用振動板を構成したものである。さらに、このスピーカ用振動板を使用してスピーカを構成している。
【００７０】
これらの構成とすることで、スピーカ用振動板の形状安定性向上やコスト低減化を図ることができる。また内部損失、材厚、重量、剛性を最適化して周波数特性の良好化を実現することができる。さらに、接着性等の信頼性向上や外観品位の向上を図ることができるスピーカを提供することができる。
【００７１】
よって、携帯電話に代表されるマイクロスピーカや一般のスピーカに要求される性能を満足できる優れたスピーカを提供することができ、その工業的価値は非常に大なるものである。
【図面の簡単な説明】
【図１】 本発明の一実施の形態におけるスピーカ用振動板の断面図
【図２】 本発明の他の実施の形態におけるスピーカ用振動板の断面図
【図３】 本発明の他の実施の形態におけるスピーカ用振動板の断面図
【図４】 本発明の他の実施の形態におけるスピーカ用振動板の断面図
【図５】 本発明の他の実施の形態におけるスピーカ用振動板の断面図
【図６】 本発明の一実施の形態におけるスピーカの断面図
【図７】 従来のスピーカ用振動板の断面図
【符号の説明】
２１ マグネット
２２ 上部プレート
２３ ヨーク
２４ 磁気回路
２５ 磁気ギャップ
２６ フレーム
２７ スピーカ用振動板
２７Ａ スピーカ用振動板
２７Ｂ スピーカ用振動板
２７Ｃ スピーカ用振動板
２７Ｄ スピーカ用振動板
２７ｄ スピーカ用振動板の一部
２８ ボイスコイル
３０ 基材
３０Ａ 基材
３０Ｂ 基材
３１ エラストマー層
３１Ａ エラストマー層
３１Ｂ エラストマー層
３１Ｃ エラストマー層
３１Ｄ エラストマー層[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a speaker diaphragm and a speaker using the same.
[0002]
[Prior art]
The diaphragm used for the microspeaker for the cellular phone is a diaphragm 7 having a shape shown in FIG. A micro speaker is configured using the diaphragm 7.
[0003]
Even when applied to general speakers, particularly tweeters, the same configuration as described above was adopted.
[0004]
Here, the physical properties required for the diaphragm 7 are directed by the balance between the square root of the sound speed: E (Young's modulus) / p (specific gravity) and the internal loss, so that the sound quality is improved and f0 is reduced (f0: lowest). (Resonance frequency).
[0005]
Conventionally, polyethylene naphthalate (PEN), polyetherimide (PEI) or the like is used as the diaphragm. Further, a method of laminating a metal thin plate on a resin film as disclosed in Japanese Patent Application Laid-Open No. 11-266493 has been proposed, but this makes it possible to achieve high sound quality but makes it difficult to reduce f0. Japanese Patent Application Laid-Open No. 03-57400 also proposes a sandwich structure for high elastic modulus and high internal loss.
[0006]
[Problems to be solved by the invention]
Since PEN has a large Young's modulus of 6000 MPa, it is necessary to extremely reduce the diaphragm thickness in order to reduce f0 in a cellular phone speaker that is required to have a low minimum resonance frequency (f0). For this reason, in PEN having high crystallinity, the variation in dimensional accuracy increases, and this variation leads to variations in various characteristics of the speaker. Therefore, since it was too thin, it had the subject that dimensional accuracy and various characteristics became unstable.
[0007]
PEI has a Young's modulus of 2800 MPa, which is more flexible than PEN, and can secure a thickness that maintains dimensional accuracy even when f0 is designed to be small. However, the internal loss (tan δ) is about 0.02 near room temperature (PEN is about 0.04), and rolling and the like are liable to occur, resulting in a large distortion and a deterioration in sound quality.
[0008]
Therefore, an object of the present invention is to provide a diaphragm that can satisfy a reduction in f0, an appropriate material thickness, a low elastic modulus, and a high internal loss, particularly in a small speaker.
[0009]
[Means for Solving the Problems]
An object of the present invention is to provide a loudspeaker diaphragm that has high sound quality and low f0.
[0010]
That is, the present invention has the following configuration.
[0011]
According to the first aspect of the present invention, the surface of a resin base material having a Young's modulus of 2500 MPa or more, an internal loss of 0.03 or less , and a thickness of 60% to 90% of the whole is crosslinked. Hydrolysis condensation type urethane elastomer, hydrolysis condensation type silicone elastomer, addition reaction type silicone elastomer, hydrolysis condensation type hydrocarbon elastomer, fluorine elastomer A base plate provided with any of the above elastomer layers is press-molded or vacuum-molded to form a speaker diaphragm. With this configuration, it is possible to improve the productivity of a speaker diaphragm that can satisfy a low elastic modulus and a high internal loss.
[0012]
Moreover, the mold releasability of the speaker diaphragm can be improved by configuring the elastomer layer as a cross-linked elastomer.
[0013]
Furthermore, the cost of the speaker diaphragm can be reduced by configuring the cross-linked elastomer as a urethane elastomer.
[0014]
Furthermore, the heat resistance and temperature characteristics of the speaker diaphragm can be stabilized by configuring the cross-linked elastomer as a silicone elastomer.
[0015]
Furthermore, the internal loss of the speaker diaphragm can be increased by configuring the cross-linked elastomer as a hydrocarbon-based elastomer.
[0016]
Furthermore, the mold release property and heat resistance of the speaker diaphragm can be particularly improved by configuring the cross-linked elastomer as a fluorine-based elastomer.
[0017]
According to the second aspect of the present invention, a speaker diaphragm is formed by providing an elastomer layer on the surface of a base material made of a resin having a Young's modulus of 2500 MPa or more and an internal loss of 0.02 or less. is there. With this configuration, it is possible to realize a speaker diaphragm that can satisfy a low elastic modulus and a high internal loss by using a base material having an internal loss smaller than that of the first aspect.
[0018]
According to a third aspect of the present invention, a speaker diaphragm is formed by providing an elastomer layer on the front and back surfaces of a resin base material. With this configuration, it is possible to realize a diaphragm that can satisfy further lower elastic modulus and higher internal loss due to the effect over both surfaces of the substrate.
[0019]
According to a fourth aspect of the present invention, the loudspeaker diaphragm according to any one of the first to third aspects is constituted by using a base material of polyetherimide (PEI). With this configuration, the reliability of the speaker diaphragm can be improved.
[0020]
According to a fifth aspect of the present invention, the speaker diaphragm according to the third aspect is constituted by two or more types of cross-linked elastomers according to the first aspect. With this configuration, it is possible to freely set a low elastic modulus and a high internal loss of the diaphragm.
[0021]
The invention according to claim 6 of the present invention is the speaker diaphragm according to any one of claims 1 to 5 , wherein one or more elastomer layers are provided on two or more substrates to form a multilayer structure. With this configuration, it is possible to further improve the low elastic modulus and high internal loss of the speaker diaphragm, and further freely set the values.
[0022]
According to a seventh aspect of the present invention, the loudspeaker diaphragm according to any one of the first to sixth aspects is configured by varying the thickness of the base material depending on the place when the base material is molded. With this configuration, it is possible to reduce the elastic modulus and the high internal loss at a specific position of the speaker diaphragm, and to control unnecessary resonance of the speaker diaphragm.
[0023]
The invention of claim 8 of the present invention, a part or all of any one of the speaker diaphragm of claim 7 according to claims 1, any one of a speaker according to claim 7 according to claims 1 A diaphragm for a speaker is configured by joining a part of the diaphragm for a speaker. With this configuration, it is possible to achieve a low elastic modulus and a high internal loss at a specific position, and it is possible to control unnecessary resonance.
[0024]
According to a ninth aspect of the present invention, a speaker is configured by using the speaker diaphragm according to any one of the first to eighth aspects. With this configuration, by reducing the elastic modulus and the high internal loss of the diaphragm, it is possible to improve the sound quality and characteristics of the speaker, expand the low-frequency reproduction band, and reduce unnecessary resonance.
[0025]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
[0026]
The diaphragm used in the present invention has a multilayer structure in which an elastomer layer is provided on the front, back or one side of a resin base material.
[0027]
(Embodiment 1)
Hereinafter, the first, second, and fourth aspects of the present invention will be described using the first embodiment.
[0028]
FIG. 1 is a sectional view of a speaker diaphragm 27 according to an embodiment of the present invention. That is, the invention described in claim 1 is configured such that the speaker diaphragm 27 is formed by providing the elastomer layer 31 on the surface of the base material 30 made of resin. Here, the base material 30 made of this resin is formed from a resin having a Young's modulus of 2500 MPa or more, an internal loss of 0.03 or less , and a thickness of 60% to 90% of the whole . Then, on the surface of the resin base material 30, a hydrolytic condensation type urethane elastomer, a hydrolytic condensation type silicone elastomer, an addition reaction type silicone elastomer, a hydrolyzing type, having a large molecular weight between cross-linking points. A diaphragm for a speaker is formed by providing an elastomer layer of either a condensation-type hydrocarbon-based elastomer or a fluorine-based elastomer, followed by press molding or vacuum molding.
[0029]
That is, the diaphragm 27 is formed into a required shape as shown in FIG. 1, specifically, a disk-shaped one is processed into a circle at the portion A in FIG. 1 , and the curved surface state is made different inside and outside. That is, the diaphragm 30 has the base material 30 formed into a required shape by a method such as press molding using a mold or vacuum molding. With this configuration, the speaker diaphragm 27 that can satisfy the low elastic modulus and the high internal loss can be realized with high productivity .
[0030]
Thus, the resin of the base material 30 can be used as long as the Young's modulus is 2500 MPa or more and the internal loss is 0.03 or less. Although many of resins generally called engineering plastics such as PEI and aromatic polyimide can be mentioned, PEI having a relatively low Young's modulus and small internal loss is preferable as the elastomer layer 31 in terms of increasing internal loss.
[0031]
Next, the material thickness of the speaker diaphragm 27 used in the present invention will be described.
[0032]
Since the speaker diaphragm 27 used in the present invention is used for a small speaker, it is 100 μm or less, preferably 50 μm or less, and most preferably 30 μm or less. Moreover, when it becomes too thin, problems, such as a dimensional accuracy, will generate | occur | produce.
[0033]
If the thickness of the resin base material 30 and the elastomer layer 31 is not 50% or more of the total thickness of the resin base material 30, the diaphragm thickness becomes larger than necessary when sound pressure is output as a speaker. End up. However, when the base material 30 becomes 95% or more of the whole, the effect of the elastomer layer 31 becomes difficult to obtain. Preferably, the resin base material 30 has a thickness of 60% to 90% of the whole.
[0034]
The speaker diaphragm 27 made of the material of the present invention and formed into a dome shape as shown in FIG. 1 has a large internal loss of the material, prevents rolling, and becomes a speaker diaphragm capable of achieving high sound quality and low f0.
[0035]
The invention according to claim 2 uses the base material 30 of FIG. 1 made of a resin having a Young's modulus of 2500 MPa or more and an internal loss of 0.02 or less. With this configuration, it is possible to realize the speaker diaphragm 27 that can satisfy the low elastic modulus and the high internal loss by using the base material 30 having the internal loss smaller than that of the first aspect.
[0036]
Next, invention of Claim 4 makes the base material 30 polyether imide (PEI). According to this configuration, it is possible to realize an improvement in reliability such as countermeasures against cracking of the diaphragm due to an effect as a physical property strong in reliability of the polyetherimide (PEI) which is the base material 30.
[0037]
Next, the details of the elastomer layer 31 will be described.
[0038]
By making the elastomer layer 31 a cross-linked elastomer, the mold releasability of the speaker diaphragm 27 can be improved. Moreover, it is preferable at the point that the adhesiveness with respect to a metal mold | die at the time of secondary shaping | molding (at the time of shaping | molding to the diaphragm 27 for speakers) is small.
[0039]
The cross-linked elastomer by a urethane elastomer, it is possible to reduce the cost of the speaker diaphragm 27. For this reason, if a crosslinkable elastomer having a molecular weight between crosslink points is too small, it cannot be formed into a dome shape as shown in FIG. Urethane crosslinks between the molecular weight is relatively large hydrolytic condensation type (moisture curing) Therefore, hydrolytic condensation type silicone, an addition reaction type silicone, pressurized hydrolysis condensation type of hydrocarbon-based elastomer (e.g., isobutylene-based, What hardened isoprene type | system | group is more preferable.
[0040]
The cross-linked elastomer by a silicone elastomer, heat resistance of the speaker diaphragm 27, it is possible to stabilize the temperature characteristic.
[0041]
The cross-linked elastomer by a hydrocarbon-based elastomer, it is possible to increase the internal loss of the speaker diaphragm 27.
[0042]
By making the cross-linkable elastomer into a fluorine-based elastomer, the mold releasability and heat resistance of the speaker diaphragm 27 can be particularly improved.
[0043]
Among these, the most preferable combination is a combination of PEI and hydrolytic condensation type urethane in consideration of cost, expansion of internal loss, and reduction of adhesiveness during molding. Furthermore, although it becomes expensive, PEI and silicone (the hardening form is not ask | required) are preferable at a heat resistant point.
[0044]
(Embodiment 2)
Hereinafter, with reference to the second embodiment will be described the invention described in particular claims 3 and 5 of the present invention.
[0045]
FIG. 2 shows a cross-sectional view of the speaker diaphragm 27A in the present embodiment. According to the third aspect of the present invention, as shown in FIG. 2, the speaker diaphragm 27 </ b> A is configured by providing elastomer layers 31 </ b> A and 31 </ b> B on both the front and back surfaces of the base material 30. With this configuration, it is possible to realize the speaker diaphragm 27 </ b> A that can satisfy further lower elastic modulus and higher internal loss due to the effects on both surfaces of the diaphragm.
[0046]
According to a fifth aspect of the present invention, the speaker-type diaphragm 27A according to the third aspect is constituted by the two or more types of elastomers according to the first aspect of the crosslinked elastomer. With this configuration, it is possible to freely set the low elastic modulus and high internal loss of the speaker diaphragm 27A.
[0047]
(Embodiment 3)
Hereinafter, with reference to the third embodiment will be described the invention described in particular claim 6 of the present invention.
[0048]
FIG. 3 shows a cross-sectional view of the speaker diaphragm 27B in the present embodiment. According to the sixth aspect of the present invention, as shown in FIG. 3, a speaker diaphragm having a multilayer structure in which one or more elastomer layers 31C and 31D are provided on two or more resin base materials 30A and 30B. 27B is formed. With this configuration, the low elastic modulus and high internal loss of the speaker diaphragm 27B can be further improved, and the values can be freely set.
[0049]
(Embodiment 4)
Hereinafter, with reference to the fourth embodiment will be described the invention described in particular claim 7 of the present invention.
[0050]
FIG. 4 shows a cross-sectional view of a speaker diaphragm 27C according to an embodiment of the present invention. According to the seventh aspect of the present invention, the thickness of the diaphragm 27C at the time of forming the diaphragm 27C is variable depending on the location, specifically, the central portion is thick and the outer periphery is thin. With this configuration, it is possible to reduce the elastic modulus (thin wall) and increase the internal loss (thick wall) at a specific position of the speaker diaphragm 27C, and to control unnecessary resonance.
[0051]
(Embodiment 5)
Hereinafter, the invention described in the eighth aspect of the present invention will be described with reference to the fifth embodiment.
[0052]
FIG. 5 shows a cross-sectional view of the speaker diaphragm 27D in the present embodiment. According to an eighth aspect of the present invention, any one of the speaker diaphragms according to the first to seventh aspects (for example, 27 in FIG. 1) and any one of the first to seventh aspects. A speaker diaphragm 27D is formed by joining a part (ring shape) 27d of two speaker diaphragms (for example, 27 in FIG. 1). With this configuration, it is possible to reduce the elastic modulus at the specific position of the diaphragm 27D (the outer periphery of the A portion) and increase the internal loss (the inner periphery of the A portion), and to control unnecessary resonance.
[0053]
(Embodiment 6)
Hereinafter, with reference to the sixth embodiment will be described the invention described in particular claim 9 of the present invention.
[0054]
FIG. 6 shows a cross-sectional view of a speaker according to an embodiment of the present invention. The invention according to claim 9 of the present invention is a speaker constituted by using any one of the speaker diaphragms 27 and 27A to 27D according to claims 1 to 8 .
[0055]
In FIG. 6, a magnetized magnet 21 is sandwiched between an upper plate 22 and a yoke 23 to constitute an inner magnet type magnetic circuit 24. A frame 26 is coupled to the yoke 23 of the magnetic circuit 24. The speaker diaphragm 27 according to any one of claims 1 to 8 is bonded to the inner peripheral edge of the frame 26.
[0056]
A cylindrical voice coil 28 is coupled to the lower surface of the A portion of the speaker diaphragm 27, and the voice coil 28 is coupled so as to fit into the magnetic gap 25 of the magnetic circuit 24.
[0057]
That is, by reducing the elastic modulus and the high internal loss of the speaker diaphragm 27, it is possible to improve the sound quality and characteristics of the speaker, expand the low-frequency reproduction band, and reduce unnecessary resonance.
[0058]
【Example】
An embodiment of the present invention will be shown below.
[0059]
Example 1
A diaphragm for speakers (FIG. 2) sandwiching the front and back surfaces of a PEI (base material 30) of 6 μm with Young's modulus of 2800 MPa, internal loss of 0.019 and 1.5 μm addition reaction type silicone (elastomer layer 31). shape). The internal loss of the composite diaphragm of Example 1 was 0.040.
[0060]
(Example 2)
Diaphragm for 2-layer speaker of 3 μm hydrolytic condensation type (moisture curing type) urethane (elastomer layer 31) and PEI (base material 30) of 6 μm with Young's modulus of 2800 MPa, internal loss of 0.019 (FIG. 1) Shape).
[0061]
The internal loss of the speaker diaphragm of Example 2 was 0.034.
[0062]
(Comparative Example 1)
A loudspeaker diaphragm for PEI (base material 30) having a Young's modulus of 2800 MPa and an internal loss of 0.019 and having a thickness of 7 μm.
[0063]
From the above configuration, it can be seen that the internal loss of Example 1 and Example 2 can be larger than that of Comparative Example 1.
[0064]
Further, f0 and distortion are summarized below.
[0065]
[Table 1]

[0066]
From Table 1, it can be seen that Example 1 and Example 2 can achieve lower f0 and lower distortion than Comparative Example 1.
[0067]
These speaker diaphragms are desirable in terms of shape stability and cost, and can satisfy internal loss, material thickness, and weight required for a micro speaker.
[0068]
With the above-described configuration, it is possible to provide a speaker that can satisfy the performance required for a micro speaker represented by a mobile phone or a general speaker.
[0069]
【The invention's effect】
As described above, the present invention constitutes a speaker diaphragm having a multilayer structure by providing an elastomer layer on the front, back or one side of a resin substrate. Furthermore, a speaker is configured using this speaker diaphragm.
[0070]
With these configurations, the shape stability of the speaker diaphragm can be improved and the cost can be reduced. In addition, the internal characteristics, thickness, weight and rigidity can be optimized to improve the frequency characteristics. Furthermore, it is possible to provide a speaker capable of improving reliability such as adhesiveness and improving appearance quality.
[0071]
Therefore, it is possible to provide an excellent speaker that can satisfy the performance required for a micro speaker typified by a cellular phone or a general speaker, and its industrial value is very large.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a speaker diaphragm according to an embodiment of the present invention. FIG. 2 is a cross-sectional view of a speaker diaphragm according to another embodiment of the present invention. FIG. 4 is a cross-sectional view of a speaker diaphragm according to another embodiment of the present invention. FIG. 5 is a cross-sectional view of a speaker diaphragm according to another embodiment of the present invention. 6 is a cross-sectional view of a speaker according to an embodiment of the present invention. FIG. 7 is a cross-sectional view of a conventional speaker diaphragm.
21 Magnet 22 Upper plate 23 Yoke 24 Magnetic circuit 25 Magnetic gap 26 Frame 27 Speaker diaphragm 27A Speaker diaphragm 27B Speaker diaphragm 27C Speaker diaphragm 27D Speaker diaphragm 27d Part of speaker diaphragm 28 Voice Coil 30 Base material 30A Base material 30B Base material 31 Elastomer layer 31A Elastomer layer 31B Elastomer layer 31C Elastomer layer 31D Elastomer layer

Claims (9)

Hydrolytic condensation on the surface of a resin base material having a Young's modulus of 2500 MPa or more, an internal loss of 0.03 or less , and a thickness of 60% to 90% of the whole, and having a high molecular weight between crosslinking points. A base material provided with an elastomer layer of any of urethane type elastomers, hydrolytic condensation type silicone elastomers, addition reaction type silicone elastomers, hydrolytic condensation type hydrocarbon elastomers, and fluoroelastomers press molding or vacuum forming to the diaphragm for ing speaker.   2. The speaker diaphragm according to claim 1, wherein a resin base material having an internal loss of 0.02 or less is used.   The speaker diaphragm according to claim 1 or 2, wherein an elastomer layer is provided on the front and back surfaces of the resin base material. The speaker diaphragm according to any one of claims 1 to 3 , wherein the base material is polyetherimide (PEI).   4. The loudspeaker diaphragm according to claim 3, wherein an elastomer layer is constituted by the two or more types of cross-linked elastomers according to claim 1.   The diaphragm for a speaker according to any one of claims 1 to 5, wherein the speaker diaphragm has a multilayer structure composed of two or more resin base materials and one or more elastomer layers. The speaker diaphragm of claim 1 wherein is varied depending on the location of the wood thickness of the base material during molding of the substrate. Some or all of any one of the speaker diaphragm of claim 7 according to claims 1, speaker diaphragm bonding the diaphragm substrate for any one of a speaker according to claim 7 according to claims 1 . A speaker using the speaker diaphragm according to any one of claims 1 to 8 .

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