Diaphragm for electroacoustic transducer and electroacoustic transducer

Abstract

To provide a novel diaphragm in which an edge is fixed around a body, and to provide an electroacoustic transducer including the diaphragm.SOLUTION: A diaphragm for an electroacoustic transducer, comprising: a body including a fiber material; and an edge including an elastomer, wherein the diaphragm has a laminated portion in which the body and the edge overlap each other, and the laminated portion is in a state where the elastomer included in the edge enters the body.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a diaphragm for an electroacoustic transducer and an electroacoustic transducer. [Background technology]

[0002] An electroacoustic transducer has a diaphragm, which is a member that vibrates in response to an electric signal or sound wave. A typical diaphragm has a vibrating part called a body and a member called an edge fixed around the periphery of the body.

[0003] Known methods for fixing the edge to the body of a diaphragm include a method for fixing the edge to the body using an adhesive and a method for fixing the edge to the body without using an adhesive. For example, Patent Document 1 describes a method for fixing the edge to the body without using an adhesive, in which a first resin material contained in the body and a second resin material contained in the edge are melted and tightly attached to each other. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 7-162991 Summary of the Invention [Problem to be solved by the invention]

[0005] The method described in Patent Document 1 cannot be applied, for example, when the fuselage does not contain a resin material. In view of the above circumstances, an object of one embodiment of the present disclosure is to provide a novel diaphragm having an edge fixed to the periphery of a body, and an electro-acoustic transducer including this diaphragm. [Means for solving the problem]

[0006] Specific means for solving the above problems include the following aspects. <1> a body including a textile material and an edge including an elastomer; a laminated portion where the body and the edge overlap, The laminated portion is a diaphragm for an electro-acoustic transducer, in which the elastomer contained in the edge penetrates into the body. <2> The body has a concave-convex structure on the surface, and the elastomer contained in the edge is embedded in the concave-convex structure. <1> The diaphragm for an electroacoustic transducer according to claim 1. <3> The body has a through hole, and the elastomer included in the edge is in a state of being inserted into the through hole. <1> or <2> The diaphragm for an electroacoustic transducer according to claim 1. <4> The edge is an injection molded body. <1> ~ <3> 10. The diaphragm for an electroacoustic transducer according to claim 9, wherein the diaphragm is a diaphragm for an electroacoustic transducer. <5> The elastomer comprises a thermoplastic elastomer. <1> ~ <4> 10. The diaphragm for an electroacoustic transducer according to claim 9, wherein the diaphragm is a diaphragm for an electroacoustic transducer. <6> <1> ~ <5> An electroacoustic transducer comprising the diaphragm for an electroacoustic transducer according to any one of claims 1 to 4. [Effects of the Invention]

[0007] According to one embodiment of the present disclosure, there is provided a novel diaphragm having edges fixed around a body, and an electro-acoustic transducer including the diaphragm. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a cross-sectional view schematically illustrating an example of the configuration of an electro-acoustic transducer according to the present disclosure. [Figure 2A] FIG. 2A is a cross-sectional view that schematically illustrates an example of the configuration of a laminated portion of a diaphragm of the present disclosure. [Figure 2B] FIG. 2B is a cross-sectional view that schematically illustrates an example of the configuration of a laminated portion of a diaphragm of the present disclosure. [Figure 2C] FIG. 2C is a cross-sectional view that schematically illustrates an example of the configuration of a laminated portion of a diaphragm of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments according to the present disclosure will be described. These descriptions and examples are intended to exemplify embodiments according to the present disclosure and are not intended to limit the scope of the invention.

[0010] In the present disclosure, a numerical range indicated using "to" indicates a range that includes the numerical values ​​before and after "to" as the lower and upper limits, respectively.

[0011] In the numerical ranges described in stages in this disclosure, the upper or lower limit value described in one numerical range may be replaced with the upper or lower limit value of another numerical range described in stages. Furthermore, in the numerical ranges described in this disclosure, the upper or lower limit value of that numerical range may be replaced with a value shown in the examples.

[0012] In the present disclosure, each component may contain multiple corresponding substances. When referring to the amount of each component in a composition in the present disclosure, if multiple substances corresponding to each component are present in the composition, the total amount of the multiple substances present in the composition is meant unless otherwise specified.

[0013] When describing embodiments of the present disclosure with reference to the drawings, the embodiments of the present disclosure are not limited to the configurations shown in the drawings. The dimensions, shapes, and the like of the components shown in the drawings are conceptual, and the embodiments of the present disclosure are not limited thereto.

[0014] <Diaphragm for electroacoustic transducer> The electroacoustic transducer diaphragm of the present disclosure comprises: a body including a textile material and an edge including an elastomer; a laminated portion where the body and the edge overlap, The laminated portion is in a state where the elastomer contained in the edge penetrates into the body.

[0015] In this disclosure, the term "electroacoustic transducer" refers to a device that converts an electrical signal into sound (a speaker) or a device that converts sound into an electrical signal (a microphone). The term "diaphragm for an electroacoustic transducer" refers to a member that vibrates in response to an electrical signal or sound wave received by the electroacoustic transducer. Hereinafter, the electroacoustic transducer diaphragm may be simply referred to as a "diaphragm."

[0016] In this disclosure, the term "body" refers to a member that corresponds to the part of the diaphragm that vibrates due to an electric signal or sound wave. In the present disclosure, the term "edge" refers to a member corresponding to the portion of the diaphragm that is connected to the main body of the electro-acoustic transducer.

[0017] The diaphragm of the present disclosure has a laminated portion where the body and the edge overlap, and the laminated portion has the elastomer contained in the edge embedded in the body. More specifically, the elastomer has embedded in the gaps around the fiber material contained in the body. This creates an anchor effect between the body and the edge in the laminated portion, resulting in excellent bonding strength. The diaphragm of the present disclosure has superior durability when the body and edge are fixed together compared to when they are fixed using the adhesive action of an adhesive or the molten adhesion action of a resin. In the diaphragm of the present disclosure, the edges are fixed to the body without using adhesive, so there is no need to worry about the acoustic characteristics of the diaphragm being affected by an adhesive layer formed between the body and the edges.

[0018] (body) The body comprises a textile material. In the present disclosure, a fibrous material refers to an object having a fibrous form, and the material thereof is not particularly limited. The shape (thickness, length, etc.) of the fiber material is not particularly limited as long as it allows the elastomer contained in the edge to penetrate into the body in the laminated portion.

[0019] The fiber material may be made from either a plant-based or non-plant-based material. Examples of plant-based raw materials include wood (coniferous or broad-leaved trees), bamboo, cotton, hemp, and straw. Non-vegetable raw materials include resin, petroleum, carbon, glass, metal, ceramic, and animal raw materials (wool, silk, etc.). The fibrous material may be a material used in papermaking (pulp). The fiber material may be a recycled material obtained by recycling waste paper or the like. The body may contain only one type of fiber material, or two or more types.

[0020] Examples of the form of the body containing the fibrous material include paper, woven fabric, nonwoven fabric, and the like.

[0021] The body may be made of only a fibrous material, or may contain a fibrous material and a material other than a fibrous material. When the body contains a material other than a fibrous material, the amount of material is preferably such that the body is sufficiently filled with elastomer. Materials other than the fiber material include additives such as inorganic fillers, colorants, and binders.

[0022] The thickness of the body is not particularly limited, and can be set depending on the type, use, size, etc. of the electroacoustic transducer to which the diaphragm is applied. From the viewpoint of ensuring the rigidity of the diaphragm, the thickness of the body is preferably 0.1 mm or more, more preferably 0.15 mm or more, and even more preferably 0.2 mm or more. From the viewpoint of reducing the weight of the diaphragm, the thickness of the body is preferably 2.0 mm or less, more preferably 1.0 mm or less, and even more preferably 0.5 mm or less.

[0023] The shape of the body is not particularly limited, and can be set according to the type, use, size, etc. of the electroacoustic transducer to which the diaphragm of the present disclosure is applied. The body may be generally conical in shape with an opening in the center.

[0024] (Edge) The edge comprises an elastomer. In the present disclosure, elastomer refers to a polymer compound that exhibits rubber elasticity. Elastomers are broadly classified into thermoplastic elastomers and rubber (thermosetting elastomers). The elastomer contained in the edge may be either a thermoplastic elastomer or rubber (thermosetting elastomer), or may be a combination of a thermoplastic elastomer and rubber.

[0025] Thermoplastic elastomers contained in the edge include styrene-based thermoplastic elastomers (TPS), olefin-based thermoplastic elastomers (TPO), urethane-based thermoplastic elastomers (TPU), ester-based thermoplastic elastomers (TPC), amide-based thermoplastic elastomers (TPA), thermoplastic rubber crosslinks (TPV), and other thermoplastic elastomers such as vinyl chloride-based thermoplastic elastomers (TPZ).

[0026] The rubber contained in the edge may be a diene rubber or a non-diene rubber. Specific examples of diene rubbers include natural rubber (NR), isoprene rubber (IR), butadiene rubber (BR), styrene-butadiene rubber (SBR), chloroprene rubber (CR), and acrylonitrile-butadiene rubber (NBR). Specific examples of non-diene rubbers include ethylene-propylene-diene rubber (EPDM, also known as ethylene-propylene rubber), butyl rubber (IIR), urethane rubber (U), silicone rubber (Q), chlorosulfonated polyethylene (CSM), chlorinated polyethylene (CM), acrylic rubber (ACM), epichlorohydrin rubber (CO or ECO), and fluororubber (FKM).

[0027] The edge preferably contains a thermoplastic elastomer, and more preferably contains a mixture A of two or more thermoplastic elastomers, or a mixture B of a thermoplastic elastomer and rubber. Mixture A preferably contains an olefin-based thermoplastic elastomer and a styrene-based thermoplastic elastomer. Mixture B preferably contains an olefin-based thermoplastic elastomer and a non-diene-based rubber, and more preferably contains an olefin-based thermoplastic elastomer and an ethylene-propylene-diene rubber.

[0028] The edge may consist solely of elastomer or may include elastomer and non-elastomer materials. If the edge includes a material other than elastomer, the amount is preferably sufficient to form a state in which the elastomer is embedded in the body. Materials other than the elastomer include additives such as inorganic fillers, colorants, and binders. In this disclosure, when the edge material is a mixture of an elastomer and a non-elastomer material, the mixture may be referred to as "elastomer."

[0029] The thickness of the edge is not particularly limited and can be selected depending on the size of the diaphragm, the purpose of use, etc. The thickness of the edge may be selected from the range of 15 μm to 5 mm, for example.

[0030] (Laminated part) The diaphragm of the present disclosure has a laminated portion where the body and the edge overlap, and the laminated portion is in a state where the elastomer contained in the edge penetrates into the body. In this disclosure, "a state in which the elastomer contained in the edge penetrates into the fuselage" means a state in which at least a portion of a recess or void present on the surface or inside of the fuselage is filled with an elastomer that is continuous with the main body of the edge. In the laminated portion, the region where the elastomer contained in the edge penetrates into the body may be present as a layer on the surface of the body that contacts the edge. The depth of the region where the elastomer contained in the edge penetrates into the body (depth from the surface of the body) is not particularly limited as long as the desired bonding strength between the body and the edge is obtained.

[0031] The laminated portion may be in a state where the body and the edge are in contact on one side of the body, or in a state where the body and the edge are in contact on both sides of the body. From the viewpoint of ensuring the bonding strength between the body and the edge, it is preferable that the laminated portion be in a state where the body and the edge are in contact on both surfaces of the body.

[0032] In the diaphragm of the present disclosure, the proportion of the laminated portion to the total area of ​​the body is not particularly limited, and can be selected from the range of 1% to 50%, for example. The ratio is a percentage of a value calculated from the total area X of the body and the area Y of the portion where the body and the edge overlap, using the following formula: Y / X.

[0033] From the viewpoint of ensuring the bonding strength between the body and the edge, it is preferable that the body has an uneven structure on the surface and that the elastomer contained in the edge penetrates into this uneven structure. The uneven structure on the surface of the fuselage may be formed by a fiber material contained near the surface of the fuselage and the gaps around it, or may be formed on the surface of the fuselage by other methods.

[0034] From the viewpoint of further increasing the bonding strength between the body and the edge, the body may have a through-hole, and the elastomer contained in the edge may fill this through-hole. In the present disclosure, a through hole refers to an opening that communicates from one surface of the body to the other surface. The through hole in the body can be formed by a known method.

[0035] (Method of manufacturing the diaphragm) The diaphragm of the present disclosure may be produced, for example, by bringing a flowable elastomer into contact with the portion of the body that corresponds to the laminated portion. By contacting a fluid elastomer with the portion of the fuselage corresponding to the laminated portion, for example, it is possible to fill at least a portion of the gaps around the fiber material contained in the fuselage with the elastomer, thereby creating a state in which the elastomer has penetrated into the fuselage. When creating a state in which the elastomer has penetrated into the fuselage, it is preferable to form an edge containing the elastomer around the fuselage. The method for carrying out the step of bringing the flowable elastomer into contact with the portion of the body corresponding to the laminated portion is not particularly limited, and can be carried out by any known method. From the viewpoint of work efficiency, etc., it is preferable to carry out the above step by injection molding.

[0036] A method for producing the diaphragm of the present disclosure by injection molding includes placing a body in a mold of an injection molding machine and then injecting a fluid elastomer into the mold. The injection molding is preferably carried out so that the elastomer is filled into the portion of the body corresponding to the laminated portion, and an edge including the elastomer is formed around the body. In other words, the edge included in the diaphragm of the present disclosure is preferably an injection-molded article. After the elastomer injected into the mold loses its fluidity and becomes solid, the injection-molded body (diaphragm) with the edge of the elastomer injection-molded body fixed around the body is removed from the mold. The method for solidifying the elastomer injected into the mold is not particularly limited, and can be selected from cooling solidification, heat curing, etc. depending on the type of elastomer.

[0037] (damping material) The diaphragm of the present disclosure may further include a damping material. The damping material is a member attached to the diaphragm for the purpose of adjusting the acoustic characteristics. Specific examples of the material for the damping material include resin, rubber, etc. Examples of resin include polyurethane, polystyrene, polyolefin, etc. The damping material may be in the form of foam, fiber, etc. The damping material is disposed, for example, on the entire surface or part of the back side of the diaphragm (the side that does not come into contact with the external environment when the diaphragm is mounted on an electroacoustic transducer). The damping material may be located behind either the fuselage or the edges, or behind both the fuselage and the edges.

[0038] <Electroacoustic transducer> The electro-acoustic transducer of the present disclosure includes the diaphragm of the present disclosure described above. The type, use, size, etc. of the electroacoustic transducer of the present disclosure are not particularly limited.

[0039] FIG. 1 is a cross-sectional view schematically illustrating an example of the configuration of an electro-acoustic transducer according to the present disclosure. The electroacoustic transducer 10 shown in FIG. 1 comprises a body 1, an edge 2 arranged around the body 1, a cap 3 arranged in the center of the body 1, a damper 4, a voice coil 5, and a frame 6. The materials contained in the electroacoustic transducer can be selected without particular limitation from materials generally used in electroacoustic transducers.

[0040] In the electroacoustic transducer 10, the structure consisting of the body 1 and the edge 2 corresponds to the diaphragm of the present disclosure. The diaphragm has a laminated portion X around the periphery of the body 1 where the body 1 and the edge 2 overlap. Although not shown, the laminated portion X is in a state where the elastomer contained in the edge 2 has penetrated into the body 1. Although not shown, the body 1 may have a through-hole in the laminated portion X that overlaps the edge 2, and the elastomer contained in the edge 2 may be in a state of entering this through-hole.

[0041] 2A, 2B, and 2C are cross-sectional views that schematically show an example of the configuration of a laminated portion X of a diaphragm of the present disclosure. In the following description, the back of the fuselage 1 means the surface of the fuselage 1 facing the frame 6 in Fig. 1. The front of the fuselage 1 means the surface of the fuselage 1 opposite the surface facing the frame 6 in Fig. 1. The laminated part X shown in FIG. 2A is in a state where the body 1 and the edge 2 overlap each other so that the edge 2 contacts the back and front surfaces of the body 1, respectively. The laminated part X shown in FIG. 2B is in a state where the body 1 and the edge 2 overlap each other so that the edge 2 contacts the back surface of the body 1. The laminated part X shown in FIG. 2C is in a state where the body 1 and the edge 2 overlap with each other so that the edge 2 contacts the front surface of the body 1. [Explanation of symbols]

[0042] 1. Torso 2. Edge 3 Cap 4 Damper 5 voice coil 6 frames 10 Electroacoustic Transducer

Claims

1. a body including a textile material and an edge including an elastomer; a laminated portion where the body and the edge overlap, The laminated portion is a diaphragm for an electro-acoustic transducer, in which the elastomer contained in the edge penetrates into the body.

2. 2. The diaphragm for an electroacoustic transducer according to claim 1, wherein the body has an uneven structure on the surface, and the elastomer contained in the edge is embedded in the uneven structure.

3. 2. The diaphragm for an electro-acoustic transducer according to claim 1, wherein the body has a through hole, and the elastomer contained in the edge is in a state of being embedded in the through hole.

4. 2. The diaphragm for an electro-acoustic transducer according to claim 1, wherein said edge is an injection molded body.

5. The diaphragm for an electro-acoustic transducer according to claim 1 , wherein the elastomer includes a thermoplastic elastomer.

6. An electroacoustic transducer comprising the diaphragm for an electroacoustic transducer according to any one of claims 1 to 5.

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