JP2010011436A - Speaker diaphragm, and electrodynamic loudspeaker using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a speaker diaphragm and an electrodynamic speaker using the same, capable of making compatible with the improvement of an acoustic characteristic, simplification of assembling operation, and reduction in man-hour; with respect to the speaker diaphragm integrally formed through a thermal-pressure molding with a plain-woven fabric coated by a thermoplastic resin as a main base member. <P>SOLUTION: The speaker diaphragm: is integrally formed through the thermal-pressure molding with the plain-woven fabric coated by the thermoplastic resin as the main base member; and is the diaphragm with a voice coil connected thereto, a fixture fixed to a magnetic circuit or a vibrating-plate fixing member, and an edge portion in between the diaphragm and the fixture. In a second laminate structure composing the edge portion, the coated thermoplastic resin is melted into spaces between the warp thread and the weft thread of the plain-woven fabric and cured. The second laminate structure is constituted as thinner compared with a first laminate structure composing the diaphragm and the fixture. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a speaker diaphragm integrally formed by hot press molding using a plain woven fabric coated with a thermoplastic resin as a base material, and a dome-shaped speaker diaphragm or an annular ring diaphragm using the same. The present invention relates to an electrodynamic speaker comprising

  The diaphragm used in the conventional dome type speaker is formed by forming a mixed composition layer of a vibration loss material resin and a fluorine resin directly or through a vibration loss material resin layer on the surface of the diaphragm base fabric. (Patent Document 1). In the case of coated fabrics that improve internal loss, cotton and synthetic fiber woven fabrics are impregnated with thermosetting resins such as phenolic resins, and the surface is coated with acrylic resin or urethane resin. It is most often used because adjustment of physical properties such as internal loss is relatively inexpensive and can be controlled.

  As another conventional diaphragm, there is an electrodynamic speaker diaphragm having a thin portion formed in one or more concentric circles outside a movable coil attached to the diaphragm (Patent Document 2). In addition, there is a speaker diaphragm that is integrally thermoformed with a plurality of types of synthetic resins having different melting points or a material including synthetic resin fibers and natural resin fibers so that the edge portion is thin and the trunk portion is thick ( Patent Document 3).

  Alternatively, other conventional diaphragms were provided with a metal layer of amorphous material by chemical vapor deposition on one or both sides of natural silk fiber, impregnated with phenol resin and dried, and then coated with chlorosulfonated polyethylene resin multiple times There is a speaker diaphragm formed by heat-molding a base fabric into a predetermined shape (Patent Document 4).

  In addition, in a ring type speaker having an annular ring diaphragm using a diaphragm base cloth similar to the above, in order to improve acoustic characteristics such as frequency characteristics and directivity, it is provided on the front surface of the annular ring diaphragm. Some have an equalizer or horn attached. The ring diaphragm is fixed and supported on the inner circumference, and a bullet-shaped equalizer with a size comparable to the outer diameter of the ring diaphragm is placed on the inner circumference of the ring diaphragm to improve acoustic characteristics in the high sound range. To do. Dome type speakers and ring type speakers are often used as tweeters for the high frequency range. For example, in the conventional ring type speaker by the applicant of the present invention, improvement of acoustic characteristics such as frequency characteristics including suppression of unnecessary vibration and abnormal noise, and easy assembly and reduction of the number of parts and man-hours are achieved. A magnetic circuit, a voice coil arranged in the magnetic gap of the magnetic circuit, an annular ring diaphragm connected to the voice coil, and a bullet-like equalizer arranged on the inner periphery of the ring diaphragm A ring-type speaker comprising: a ring-like equalizer arranged on the outer periphery of the ring diaphragm; and a plurality of radially extending plate-like connecting arms connecting the bullet-like equalizer and the ring-like equalizer, The arm has a first ridge line represented by an arc passing through the top end of the bullet-like equalizer in the radial cross-sectional shape, and a bullet-like icon in the radial cross-sectional shape. A second ridge line represented by an arc passing through the bottom end of the Iser, and a plate-like portion that connects the first ridge line and the second ridge line, and a circumferential sectional shape of the connecting arm represents the first ridge line. There is one defined by a first arc, a second arc representing the second ridge line having a radius equal to or larger than the radius of the first arc, and a curve representing the plate-like portion (Patent Document 5). .

  In the electrodynamic type speaker using the speaker diaphragm of these coated cloths, a diaphragm part to which a voice coil is attached, an edge part that supports the diaphragm part as a movable part so as to vibrate, and a magnetic circuit around the edge part And a fixed portion fixed to the same. Not only the material and shape of the diaphragm part, but also the shape of the edge part and the fixing structure of the fixing part affect the acoustic characteristics as a tweeter for the high frequency range. In other words, even though the physical properties required for the diaphragm portion and the physical properties required for the edge portion are different, the speaker diaphragm that integrally molds them has improved acoustic characteristics, facilitated assembly, and reduced the number of parts. There is a problem that the conventional technology may not be sufficient to achieve both reduction in man-hours. In particular, in the case of a ring diaphragm, an edge portion is required on the inner peripheral side and the outer peripheral side of the annular diaphragm portion.

Japanese Patent No. 2676158 (Fig. 1) Japanese Utility Model Publication No. 57-117889 (FIGS. 2 to 5) Japanese Utility Model Publication No. 58-155196 (Fig. 2) Japanese Patent No. 30673360 (Fig. 1) Japanese Patent No. 4042732 (FIGS. 1 and 6)

  The present invention has been made in order to solve the above-described problems of the prior art, and an object of the present invention is to make a speaker vibration integrally formed by hot press molding using a plain woven fabric coated with a thermoplastic resin as a base material. An object of the present invention is to provide a speaker diaphragm that can improve acoustic characteristics, facilitate assembly, and reduce man-hours, and an electrodynamic speaker using the speaker diaphragm.

  The speaker diaphragm of the present invention is a speaker diaphragm integrally molded by hot press molding using a plain woven fabric coated with a thermoplastic resin as a base material, and a diaphragm unit to which a voice coil is connected, a magnetic circuit or A fixing portion fixed to the vibration plate fixing member; and an edge portion defined between the vibration plate portion and the fixing portion. The second laminated structure constituting the edge portion is melted by the coated thermoplastic resin. The warp yarns and weft yarns constituting the plain woven fabric are hardened by entering, and are formed thinner than the first laminated structure constituting the diaphragm portion and the fixing portion.

  The speaker diaphragm of the present invention further includes a metal film and an oxide film formed on the metal film on the surface of the thermoplastic resin coated on the base material.

  Preferably, in the speaker diaphragm of the present invention, the thickness t2 of the second laminated structure constituting the edge portion is in the range of 50% to 80% of the thickness t1 of the first laminated structure constituting the diaphragm portion and the fixing portion. The rigidity G2 of the second laminated structure is smaller than the rigidity G1 of the first laminated structure, and the internal loss tan δ2 of the second laminated structure is larger than the internal loss tan δ1 of the first laminated structure. .

  Preferably, in the speaker diaphragm of the present invention, the warp and the weft constituting the plain woven fabric as the base material are selected from polyester, polyurethane, polyimide, and rayon monofilament yarns of synthetic fibers, and are thermoplastic. The resin is selected from a synthetic resin such as polyethylene resin, acrylic resin, and urethane resin.

  In the speaker diaphragm of the present invention, the metal forming the metal film is selected from titanium, chromium, and gold.

  In the speaker diaphragm of the present invention, the metal film is formed by physical vapor deposition and the oxide film is formed by aging.

  More preferably, in the speaker diaphragm of the present invention, the thermoplastic resin further includes foam beads.

  Preferably, in the speaker diaphragm of the present invention, the diaphragm part is an annular ring diaphragm part, and the fixing part is an inner peripheral fixing part that fixes the inner peripheral side of the ring diaphragm part, An outer peripheral fixing portion that fixes an outer peripheral side of the ring diaphragm portion, an edge portion is defined between the ring diaphragm portion and the inner peripheral fixing portion, an inner peripheral edge portion, and the ring diaphragm portion and the outer periphery And an outer peripheral edge portion defined between the fixed portion and the outer peripheral edge portion.

  In addition, an electrodynamic speaker of the present invention includes the above speaker diaphragm, a magnetic circuit, and a voice coil that is disposed in a magnetic gap of the magnetic circuit and is connected to the speaker diaphragm.

  The electrodynamic speaker according to the present invention is connected to the speaker diaphragm including the speaker diaphragm including the ring diaphragm, the magnetic circuit, the equalizer coupled to the magnetic circuit, and the magnetic gap of the magnetic circuit. A voice coil.

  Hereinafter, the operation of the present invention will be described.

  The speaker diaphragm of the present invention is a speaker diaphragm integrally molded by hot press molding using a plain woven fabric coated with a thermoplastic resin as a base material, and a diaphragm unit to which a voice coil is connected, a magnetic circuit or A fixing part fixed to the diaphragm fixing member and an edge part defined between the diaphragm part and the fixing part are provided, and these are integrally molded. In addition, an electrodynamic speaker of the present invention includes the above speaker diaphragm, a magnetic circuit, and a voice coil that is disposed in a magnetic gap of the magnetic circuit and is connected to the speaker diaphragm. The diaphragm fixing member is a member for fixing the diaphragm to the magnetic circuit or the equalizer for the fixing part of the speaker diaphragm.

  Here, the plain woven fabric used for the speaker diaphragm of the present invention is a plain woven thin silk fabric called taffeta, or a plain woven thin fabric using a filament yarn of synthetic fiber. A plain woven fabric is composed of densely woven warp and weft, and the warp and weft are multifilaments in which synthetic filament monofilament such as polyester, polyurethane, polyamide, rayon, etc. are bundled without twisting. This is a yarn configured as a yarn. The plain woven fabric is densely woven using untwisted yarn, so there is no risk of back leakage of the thermoplastic resin that is coated with a small opening ratio, and it can be used for speaker diaphragms. Is suitable.

  In the speaker diaphragm of the present invention, the first laminated structure constituting the diaphragm part and the fixed part constitutes the edge part when the thermoplastic resin is coated on the base material having the thickness t0 to have the thickness t1. The thickness t2 of the second laminated structure is formed to be thinner than the first laminated structure. That is, in the second laminated structure that constitutes the edge portion, the coated thermoplastic resin melts and penetrates into the gap between the warp and weft constituting the plain woven fabric, and is cured by hot pressing. Compared to the thickness t1, it is thinner and has a thickness t2 (50% to 80% of the thickness t1). Therefore, the rigidity G2 of the second laminated structure is smaller than the rigidity G1 of the first laminated structure, and the internal loss tan δ2 of the second laminated structure is larger than the internal loss tan δ1 of the first laminated structure. it can.

  As a result, despite the integrated speaker diaphragm, the first laminated structure of the diaphragm part and the second laminated structure of the edge part can have shapes and physical properties suitable for the respective roles. . This is because, in the second laminated structure of the edge portion to be thinned, the monofilament yarns of the plain woven fabric are easily slipped, and the coated thermoplastic resin is melted and enters the gap between the warp yarn and the weft yarn, and is cured. On the other hand, when compared with the first laminated structure of the diaphragm portion and the fixed portion that are not thinned, the layer configuration can be adjusted so that not only the thickness but also the physical properties such as Young's modulus, internal loss, and rigidity are different. This is because it is possible to achieve both improvement and ease of assembly and reduction of man-hours. When the thermoplastic resin to be coated further includes foam beads, the above physical properties including the foaming ratio are different between the first laminated structure of the diaphragm portion and the fixed portion and the second laminated structure of the edge portion. Can be adjusted as follows.

  In a more preferred case, the speaker diaphragm of the present invention further has a metal film and an oxide film formed on the metal film on the surface of the thermoplastic resin coated on the base material. The metal forming the metal film is selected from titanium, chromium, and gold, which are metals having a smaller linear expansion coefficient than the thermoplastic resin, and the metal film is formed by physical vapor deposition, that is, sputtering. An oxide film is formed by an aging method. Since the synthetic fiber constituting the plain woven fabric of the base material has a larger linear expansion coefficient than the thermoplastic resin coated on the base material, in the speaker diaphragm of the present invention, from the base material having the largest linear expansion coefficient, Next, a metal film having the smallest linear expansion coefficient is formed after the thermoplastic resin having the smallest linear expansion coefficient. Therefore, it is possible to realize a speaker diaphragm having excellent shape stability, in which internal loss can be increased and deformation due to heat hardly occurs.

  When the diaphragm part is an annular ring diaphragm part, the speaker diaphragm of the present invention is such that the fixed part is an inner peripheral fixed part that fixes the inner peripheral side of the ring diaphragm part, and the ring diaphragm. An outer peripheral fixing portion that fixes an outer peripheral side of the portion, an edge portion is defined between the ring diaphragm portion and the inner peripheral fixing portion, an inner peripheral edge portion, a ring diaphragm portion and an outer peripheral fixing portion, And an outer peripheral edge portion defined between the two. The ring further includes an equalizer connected to the magnetic circuit, and includes a diaphragm inner peripheral fixing member and a diaphragm outer peripheral fixing member for fixing the inner peripheral fixing portion and the outer peripheral fixing portion of the speaker diaphragm to the magnetic circuit or the equalizer. Type speakers are realized. Since the ring type speaker requires an inner peripheral edge portion on the inner peripheral side of the annular diaphragm portion and an outer peripheral edge portion on the outer peripheral side, each of the edge portions has the above-mentioned second laminated structure. Even in the case of a ring diaphragm in which the parts are integrated, the acoustic characteristics can be improved.

  The speaker diaphragm of the present invention and the electrodynamic speaker using the same can achieve both improvement in acoustic characteristics, ease of assembly, and reduction in man-hours.

  The speaker diaphragm of the present invention is integrally formed by hot press molding using a plain woven fabric coated with a thermoplastic resin as a base for the purpose of achieving both improvement in acoustic characteristics, ease of assembly and reduction in man-hours. A speaker diaphragm to be molded, a diaphragm part to which a voice coil is connected, a fixing part fixed to a magnetic circuit or a diaphragm fixing member, an edge part defined between the diaphragm part and the fixing part, And the second laminated structure constituting the edge portion is melted into the gap between the warp and weft yarns constituting the plain woven fabric by melting the coated thermoplastic resin and constitutes the diaphragm portion and the fixing portion. This was realized by forming a thin wall as compared with the first laminated structure.

  Hereinafter, a speaker diaphragm according to preferred embodiments of the present invention and an electrodynamic speaker using the same will be described, but the present invention is not limited to these embodiments.

  FIG. 1 is a diagram illustrating a ring speaker 1 according to a preferred embodiment of the present invention. FIG. 1A is a perspective view of the ring speaker 1 as viewed from the front, and FIG. 1B is an exploded development view illustrating the ring speaker 1. The ring type speaker 1 of the present embodiment is a speaker having a diameter of 3 cm used as a tweeter for high-frequency range reproduction. The ring type speaker 1 includes an equalizer 2 formed of resin exposed to the front side, an annular ring diaphragm 3, a voice coil 4 connected to the ring diaphragm 3, and a magnetic circuit 10. . The magnetic circuit 10 includes a yoke 11, a magnet 12, and a plate 13, and these are connected and fixed with an adhesive. The magnetic circuit 10 has an annular magnetic gap between the yoke 11 and the plate 13, and a DC magnetic field is formed in the magnetic gap.

  The equalizer 2 is made of, for example, an ABS resin having excellent moldability. The equalizer 2 has a convex external shape on the front side and forms a bullet-shaped equalizer, an outer peripheral portion 22 that forms an annular equalizer, a connecting arm portion 23 that integrally connects these, These are integrally molded with resin, and as a result, the radiation hole 20 is formed. The equalizer 2 improves the acoustic characteristics such as the reproduction frequency characteristics and suppresses unnecessary vibrations and abnormal noises, similarly to the connected equalizer included in the ring-type speaker of Patent Document 4.

  FIG. 2 is a diagram for explaining the ring diaphragm 3 of this embodiment and the voice coil 4 connected thereto. Specifically, FIG. 2 (a) is an enlarged cross-sectional view of the ring diaphragm 3 and the voice coil 4, and FIG. 2 (b) is an enlarged view of the vicinity of the inner periphery fixing portion 3c x2. These are enlarged views of the vicinity x1 of the outer periphery fixing portion 3b. The voice coil 4 is configured by winding a coil 6 around a cylindrical bobbin 5. When the ring speaker 1 is assembled, the coil 6 of the voice coil 4 connected to the ring diaphragm 3 is disposed in this magnetic gap. Therefore, when an audio signal current is supplied to the coil 6, a driving force acts on the voice coil 4 to vibrate the ring diaphragm 3 exposed from the radiation hole 20 and radiate sound waves.

  As shown in FIG. 2, the ring diaphragm 3 includes a diaphragm portion 3a to which the voice coil 4 is connected, an outer periphery fixing portion 3b and an inner periphery fixing portion 3c fixed to the magnetic circuit, and a diaphragm portion 3a and an outer periphery fixing portion. The outer peripheral edge part 3d prescribed | regulated between the parts 3b, and the inner peripheral edge part 3e prescribed | regulated between the diaphragm part 3a and the inner peripheral fixing | fixed part 3c are provided. The ring diaphragm 3 has an outer radius r1 of 19.5 mm, an inner radius r2 of 5.05 mm, a width rs of the diaphragm 3a of about 8.35 mm, and a width of the outer periphery fixing portion 3b and the inner periphery fixing portion 3c. rw is about 3.06 mm. The diaphragm portion 3a defined by two rolls connected in cross-sectional shape has one end of the bobbin 5 of the voice coil 4 connected and fixed with an adhesive on the circumference having a center radius r0 of 12.29 mm. . Moreover, the flat outer periphery fixing | fixed part 3b and the inner periphery fixing | fixed part 3c are pinched between the equalizer 2 and the magnetic circuit 10, and are fixed with an adhesive agent.

The ring diaphragm 3 of this embodiment is based on a plain weave taffeta made of polyester filament monofilament yarns with a thickness of 75 de and 100 de used as warp and weft and coated with a thermoplastic resin. . This taffeta is plain woven without twisting under conditions of the number of drivings of 110 vertical / inch and 80 horizontal / inch, and has a basis weight of 82 g / m ² . The taffeta fabric surface is coated with a chlorosulfonated polyethylene resin as an undercoat, and further coated with the same resin as the undercoat as a topcoat, and a substrate having a total basis weight of 98 g / m ² and a thickness t0 of 0.11 mm. Obtainable. Since the taffeta is densely woven using yarns that are not twisted, the opening ratio is small, and the back leakage of the resin to be coated can be reduced.

The ring diaphragm 3 is formed by using a base material having a resin coating on a taffeta at a mold temperature of 210 ° C above and below, a molding pressure of 480 kg, a molding time of 18 sec. It is molded by hot pressing under the following conditions. The shape of the ring diaphragm 3 and the thickness of each part are adjusted by the clearance of the die to be hot pressed. The diaphragm portion 3a, the outer periphery fixing portion 3b, and the inner periphery fixing portion 3c of the ring diaphragm 3 of the present embodiment can be made approximately the same as the thickness of the resin-coated base material, although each shape can be given by hot pressing. . Specifically, in the first laminated structure representing the layer structure of the diaphragm portion 3a, the outer periphery fixing portion 3b, and the inner periphery fixing portion 3c, values of the thickness t1, etc. are as follows. The shape and thickness of the vibration plate portion 3a can be variously changed by appropriately selecting a base material with a resin coating on the taffeta and adjusting the mold shape and clearance.
Example 1
First laminated structure: (diaphragm 3a, outer periphery fixing portion 3b, inner periphery fixing portion 3c)
Thickness t1 0.11mm
Fabric weight 98.0g / m ²
Density 0.89 g / cm ³
Young's modulus 9.11E + 8 dyne / cm ²
Internal loss tan δ1 0.043
Rigidity G1 1.21E-4N / m ²

On the other hand, the outer peripheral edge part 3d and the inner peripheral edge part 3e have a thickness t1 of the first laminated structure that forms the diaphragm 3a, the outer peripheral fixing part 3b, and the inner peripheral fixing part 3c by making the mold clearance narrower. It is formed thinner than. The outer peripheral edge portion 3d and the inner peripheral edge portion 3e are bent portions of the outer peripheral end and the inner peripheral end of the vibration plate portion 3a. The structure is made thin with a thickness t2. That is, as will be described later, in the second laminated structure, the coated thermoplastic resin melts and enters into the gap between the warp and weft constituting the plain woven fabric and hardens, and the thickness of the first laminated structure is obtained by hot pressing. Compared with t1, it is thinner and has a thickness t2 (50% to 80% of the thickness t1).
Example 1
Second laminated structure: (outer peripheral edge portion 3d, inner peripheral edge portion 3e)
Thickness t2 0.08mm (About 73% compared to t1)
95.6 g / m ²
Density 1.20 g / cm ³
Young's modulus 4.34E + 8 dyne / cm ²
Internal loss tan δ2 0.106
Rigidity G2 2.22E-5N / m ²

  That is, the rigidity G2 of the second laminated structure of the ring diaphragm 3 is smaller than the rigidity G1 of the first laminated structure, and the internal loss tan δ2 of the second laminated structure becomes the internal loss tan δ1 of the first laminated structure. Big in comparison. In the case of the first embodiment, even if the speaker diaphragm is formed integrally with the diaphragm portion and the edge portion by hot press molding, the outer peripheral edge portion 3d and the inner peripheral edge portion 3e are compared with the diaphragm portion 3a. The rigidity can be lowered to make it flexible and function as a compliance having a spring property, and the internal loss of the edge portion can be increased to quickly converge the inherent resonance, thereby improving the quality of reproduced audio.

  FIG. 3 is an enlarged photograph illustrating the appearance of the fabric surface of the ring diaphragm 3 of the first embodiment. 3A shows the surface of the diaphragm portion 3a, and FIG. 3B shows the surface of the outer peripheral edge portion 3d. Since the ring diaphragm 3 uses a base material with a resin coating on the taffeta, the first laminated structure of the diaphragm portion 3a may not be subjected to strong pressing pressure, so the coated resin Difficult to penetrate between woven fibers with small opening ratio. On the other hand, in the second laminated structure of the outer peripheral edge portion 3d and the inner peripheral edge portion 3e to which a strong press pressure is applied, the warp and weft yarns are not twisted, so that the monofilament yarns are easy to slip and the coating resin on the fabric surface Melts into the gaps between the monofilament yarns, thins and hardens. Thus, by using taffeta as a base material, the layer configuration of the diaphragm portion and the edge portion can be adjusted regardless of the same material, and the physical property changes as described above can be provided.

  FIG. 4 is a diagram for explaining the ring diaphragm 30 of the first comparative example and the voice coil 4 connected thereto. FIG. 5 is an enlarged photograph illustrating the appearance of the fabric surface of the ring diaphragm 30 of Comparative Example 1. That is, the ring diaphragm 30 of the comparative example 1 is not a taffeta as in the first embodiment, but uses a base material obtained by applying a resin coating to a woven fabric made of twisted yarn, and has substantially the same dimensions as the first embodiment. Even if it is, it is a diaphragm provided with the outer peripheral edge part 30d and the inner peripheral edge part 30e which are not made thin. Therefore, portions common to those in the first embodiment are denoted by common numbers and description thereof is omitted.

The ring diaphragm 30 of Comparative Example 1 is based on a polyester fiber twisted woven fabric coated with a chlorosulfonated polyethylene resin, and has a total basis weight of 120 g / m ² and a thickness t0 of 0.142 mm. It is. A woven fabric made of twisted yarn has a problem that the yarns are difficult to slip because the filament yarns are strongly entangled, and the fibers cannot follow even when a high press pressure is applied to reduce the thickness. In addition, even when using the same yarn count as the taffeta as in Example 1, the twisted yarn becomes a finer thread, and the opening ratio of the fabric increases, so the coating resin enters the opening portion, Slip between threads is suppressed.

Therefore, in the ring diaphragm 30 of the comparative example 1, the outer peripheral edge part 30d and the inner peripheral edge part 30e cannot be thinned even when a high press pressure similar to that of the ring diaphragm 3 of the first embodiment is applied. Specifically, in the ring diaphragm 30, values such as the thickness t1 are as follows.
(Comparative Example 1)
First laminated structure: (diaphragm 30a, outer periphery fixing portion 30b, inner periphery fixing portion 30c)
Thickness t1 0.142mm
120.0 g / m ²
Density 0.85 g / cm ³
Young's modulus 9.62E + 8 dyne / cm ²
Internal loss tan δ1 0.036
Rigidity G1 2.75E-4N / m ²

On the other hand, in the second laminated structure representing the layer structure of the outer peripheral edge portion 30d and the inner peripheral edge portion 30e, the values such as the thickness t2 are as follows. For example, the thickness t2 is only about 94% change compared to the thickness t1, and other numerical values are not significantly different from the first laminated structure.
(Comparative Example 1)
Second laminated structure: (outer peripheral edge portion 30d, inner peripheral edge portion 30e)
Thickness t2 0.133mm (about 94% compared to t1)
Weight per unit: 114.0 g / m ²
Density 0.86 g / cm ³
Young's modulus 9.33E + 8 dyne / cm ²
Internal loss tan δ2 0.041
Rigidity G2 2.20E-4N / m ²

  Thus, in the case of the ring diaphragm 3 of the first embodiment, since the taffeta is used as the base material, the coating resin enters between the filament yarns, so the basis weight does not change greatly, and the thickness is reduced. Density increases. On the other hand, in the ring diaphragm 30 of Comparative Example 1, since the woven fabric of twisted yarn is used as the base material, the thickness hardly changes and as a result, the density does not change, and the diaphragm portion and the edge portion. It is not possible to adjust the layer structure.

  In the case of the ring diaphragm 3 of the first embodiment using taffeta as a base material, the values of the thickness t2 and the like of the second laminated structure representing the layer structure of the outer peripheral edge part 30d and the inner peripheral edge part 30e are the diaphragm part. 3a, the outer periphery fixing portion 3b, and the inner periphery fixing portion 3c are about 73% of the thickness t1 of the first laminated structure. Preferably, the thickness t2 of the second laminated structure is, for example, as described in Example 1 below. As shown in the case of Example 2, Example 3, and Example 4 (not shown), it may be set within a range of 50% to 80% of the thickness t1 of the first laminated structure. Note that description of the common first stacked structure is omitted.

(Example 2)
Second laminated structure: (outer peripheral edge portion 3d, inner peripheral edge portion 3e)
Thickness t2 0.077mm (about 70% compared to t1)

(Example 3)
Second laminated structure: (outer peripheral edge portion 3d, inner peripheral edge portion 3e)
Thickness t2 0.079 mm (about 72% compared to t1)

Example 4
Second laminated structure: (outer peripheral edge portion 3d, inner peripheral edge portion 3e)
Thickness t2 0.06mm (about 54% compared to t1)
Weight per unit area 83.4 g / m ²
Density 1.39 g / cm ³
Young's modulus 2.12E + 8 dyne / cm ²
Internal loss tan δ2 0.114
Rigidity G2 4.58E-6N / m ²

  In any case, the rigidity G2 of the second laminated structure is smaller than the rigidity G1 of the first laminated structure, and the internal loss tan δ2 of the second laminated structure is larger than the internal loss tan δ1 of the first laminated structure. Become. Accordingly, the rigidity of the outer peripheral edge portion 3d and the inner peripheral edge portion 3e is lowered and made flexible as compared with the diaphragm portion 3a to function as a compliance having a spring property, and the internal loss of the edge portion is increased to cause inherent resonance. It is possible to quickly converge and improve the quality of reproduced audio.

  FIG. 6 is a graph showing the 1 m sound pressure frequency characteristic on the axis of the ring type speaker of this example. 6A shows the case of the ring type speaker 1 using the ring diaphragm 3 of the first embodiment, FIG. 6B shows the case of the second embodiment, and FIG. 6C shows the case of the third embodiment. FIG. 6D shows the case of the fourth embodiment. In the case of the ring type speaker 1 of the present embodiment, a large peak dip does not occur in the reproduction band of 10000 Hz or higher until the peak of the high frequency limit frequency fh at about 50000 Hz or higher is reached, and is almost flat. The frequency characteristics are shown. Thus, in the ring type speaker 1 of the present embodiment, the reproduction frequency band can be widened and the acoustic characteristics can be improved.

On the other hand, FIG. 7 is a graph showing an on-axis 1 m sound pressure frequency characteristic of a ring type speaker (not shown) of a comparative example. FIG. 7A shows the case of a ring type speaker using the ring diaphragm 30 of the above-mentioned comparative example 1, and FIG. 7B shows the case of comparative example 2 below. The comparative example 2 is a case where the thickness t2 of the second laminated structure is set to, for example, 43% of the thickness t1 of the first laminated structure, which is half or less, and it may not be preferable if the thickness is too thin. In the case of the ring type speakers of Comparative Example 1 and Comparative Example 2, a remarkable peak dip occurs in the band of about 25000 Hz to about 30000 Hz, and it can be seen that the ring diaphragm 3 vibrates in a divided manner.
(Comparative Example 2)
Second laminated structure: (outer peripheral edge portion 30d, inner peripheral edge portion 30e)
Thickness t2 0.047mm (about 43% compared to t1)

  The warp and weft constituting the plain woven fabric of the above embodiment are synthetic fiber polyesters, but are not limited thereto, and may be selected from polyurethane, polyimide, and rayon monofilament yarns. Good. Further, the thermoplastic resin is not limited to chlorosulfonated polyethylene resin, and may be selected from any one of polyethylene resin, acrylic resin, and urethane resin of other synthetic resins.

  Further, when the thermoplastic resin further includes expanded beads, the expansion ratio p1 at the thickness t1 of the first stacked structure and the expansion ratio p2 at the thickness t2 of the second stacked structure can be made different. . Specifically, Example 5 uses a substrate obtained by coating chlorosulfonated polyethylene resin containing 10% of foam beads on both surfaces of the same substrate as in Example 1 above. By making the mold clearance narrower, the outer peripheral edge portion 3d and the inner peripheral edge portion 3e have a thickness t1 of the first laminated structure constituting the diaphragm portion 3a, the outer peripheral fixing portion 3b, and the inner peripheral fixing portion 3c. The thin film is also formed in the same manner as in the other embodiments described above.

(Example 5)
First laminated structure: (diaphragm 3a, outer periphery fixing portion 3b, inner periphery fixing portion 3c)
Thickness t1 0.15mm
Weight per unit: 114.0 g / m ²
Density 0.76 g / cm ³
Young's modulus 8.93E + 8 dyne / cm ²
Internal loss tan δ1 0.054
Rigidity G1 3.01E-4N / m2
Foaming ratio p1 14%
Second laminated structure: (outer peripheral edge portion 3d, inner peripheral edge portion 3e)
Thickness t2 0.11mm (about 73% compared to t1)
Per unit weight 111.2 g / m ²
Density 1.01 g / cm ³
Young's modulus 4.25E + 8 dyne / cm ²
Internal loss tan δ2 0.133
Rigidity G2 5.66E-5N / m ²
Expansion ratio p2 16%

  As described above, since the resin to be coated contains foam beads, the difference in internal loss between the outer peripheral edge portion 3d and the inner peripheral edge portion 3e can be further increased as compared with the diaphragm portion 3a. In order to form the outer peripheral edge portion 3d and the inner peripheral edge portion 3e in a thin shape, the cloth is coated with a resin in which a foamed material such as beads is mixed with the above synthetic resin, and the vibration plate portion 3a has a predetermined mold clearance. The outer peripheral edge portion 3d and the inner peripheral edge portion 3e may be maintained in a solid state without foaming by keeping the mold clearance at about the fabric thickness.

  Next, the case where the ring diaphragm 3 further has a metal film and an oxide film formed on the metal film on the surface of the thermoplastic resin will be described. A plain weave taffeta using raw silk yarns of 75 de and 100 de made from the same monofilament yarn of polyester fiber as in Example 1 above, coated with chlorosulfonated polyethylene resin as an undercoat, and top A base material coated with the same resin as the undercoat is obtained as a coat, and a metal film and an oxide film formed on the metal film are further formed on the surface of the thermoplastic resin. Specifically, this polyester woven cloth coated with resin is placed in a sputter device in the form of a wound roll, and is applied to the coating resin surface so as to improve the adhesion between the coating resin surface and the metal film after being in a vacuum state. Plasma discharge treatment is applied, and crystal growth is performed with a target of pure titanium so as to have a film thickness of 600 ± 10%. At this time, the material feed rate is 15 cm / min, and after the sputtering process, which is a physical vapor deposition method, the winding roll is taken out from the apparatus and aged at 40 to 60 ° C./24 to 48 hr to form an oxide film on the metal surface. To form.

The ring diaphragm 3 of the present example is obtained by molding the above-mentioned sputtered material under conditions of a mold temperature of 210 ° C. above and below, a molding pressure of 480 kg, and a molding time of 18 seconds. Although it has substantially the same dimensions, basis weight, and thickness, it shows a higher internal loss. That is, in the first laminated structure of the diaphragm portion 3a, the outer periphery fixing portion 3b, and the inner periphery fixing portion 3c, since the metal film is further provided on the surface of the thermoplastic resin, the internal friction between different materials is larger. Thus, the characteristics as a speaker diaphragm can be further improved.
(Example 6)
First laminated structure: (diaphragm 3a, outer periphery fixing portion 3b, inner periphery fixing portion 3c)
Thickness t1 0.11mm
Fabric weight 98.0g / m ²
Density 0.89 g / cm ³
Young's modulus 6.34E + 9 dyne / cm ²
Internal loss tan δ1 0.076.
Rigidity G1 8.44E-4N / m ²

On the other hand, the outer peripheral edge portion 3d and the inner peripheral edge portion 3e form the diaphragm portion 3a, the outer peripheral fixing portion 3b, and the inner peripheral fixing portion 3c by narrowing the mold clearance, as in the first embodiment. The first laminated structure is formed thinner than the thickness t1. In the outer peripheral edge portion 3d and the inner peripheral edge portion 3e having a thickness t2 having a second laminated structure different from the first laminated structure described above, even if it has a metal film as in this embodiment, The coated thermoplastic resin melts and penetrates into the gap between the warp and weft constituting the plain woven fabric and hardens, and is thinner than the thickness t1 of the first laminated structure (thickness t1 is 50% to 80% of the thickness t1). %). In addition, as the prior art described in Patent Document 4 shows, when the metal film is arranged so as to be sandwiched between them, even if the thermoplastic resin coated by hot pressing is melted, Since it becomes difficult to enter the gap between the wefts, it is difficult to make the outer peripheral edge portion 3d and the inner peripheral edge portion 3e thinner than the thickness of the first laminated structure.
(Example 6)
Second laminated structure: (outer peripheral edge portion 3d, inner peripheral edge portion 3e)
Thickness t2 0.08mm (About 73% compared to t1)
95.6 g / m ²
Density 1.20 g / cm ³
Young's modulus 3.45E + 9 dyne / cm ²
Internal loss tan δ2 0.127
Rigidity G2 1.77E-4N / m ²

  That is, the rigidity G2 of the second laminated structure of the ring diaphragm 3 is smaller than the rigidity G1 of the first laminated structure, and the internal loss tan δ2 of the second laminated structure becomes the internal loss tan δ1 of the first laminated structure. Big in comparison. In the case of the sixth embodiment, even if the speaker diaphragm is formed integrally with the diaphragm portion and the edge portion by hot press molding, the outer peripheral edge portion 3d and the inner peripheral edge portion 3e are compared with the diaphragm portion 3a. The rigidity can be lowered to make it flexible and function as a compliance with spring properties, and the internal loss of the diaphragm and the edge can be further increased. As a result, the inherent resonance is quickly converged and reproduced. Voice quality can be improved.

  Here, the metal film is made of titanium, chromium, gold, which is a metal whose linear expansion coefficient is smaller than each of the synthetic fibers constituting the plain woven fabric of the base material and the thermoplastic resin coated on the base material. Is preferably selected from any of the following. For example, in the case of the present example, the linear expansion coefficient of chlorosulfonated polyethylene resin is smaller than that of polyester fibers constituting the plain woven fabric of the base material, and the linear expansion coefficient of titanium is further smaller. Therefore, since the ring diaphragm 3 of the present embodiment is configured by stacking in order of increasing linear expansion coefficient, it is more heat-induced than in the case of the prior art in which the metal film is disposed in the middle. There is an advantage that deformation hardly occurs and shape stability is excellent.

  In addition to the above titanium, the metal forming the metal film may be chromium or gold having relatively high corrosion resistance. In addition, since a metal film formed with a crystal structure by a physical vapor deposition method is further formed with an oxide film by an aging method, cracks are hardly generated even when a large pressure is applied by hot pressing. As in this embodiment, a metal film may be formed by placing a substrate coated with a thermoplastic resin in a sputtering roll in a sputtering apparatus, and the shape of the ring diaphragm 3 is obtained by hot pressing. After that, each ring diaphragm 3 may be sputtered. The physical vapor deposition method is not limited to the case of the sputtering treatment of the above-described embodiment, and may include other steps. Also, the aging treatment for forming an oxide film on the surface of the metal film is also described above. You may process by the temperature and time different from an Example.

  FIG. 8 is a graph showing 1 m sound pressure on the axis when a sine wave signal of about 1 kHz is inputted to the ring speaker 1 of the present embodiment, and is a frequency graph showing the level of the second or higher harmonic distortion. . FIG. 8A shows the case of the ring type speaker 1 using the ring diaphragm 3 of the first embodiment, and FIG. 8B shows the case of the sixth embodiment. In the case of the ring type speaker 1 of Example 6 of the present invention, it can be seen that higher-order harmonic distortion is reduced as compared with the case of Example 1. As described above, the ring type speaker 1 of this embodiment has excellent reproduction sound quality, and can improve acoustic characteristics.

  In the above-described ring type speaker of the present invention, the equalizer 2 formed of resin may be replaced with another material. For example, the equalizer 2 serving also as a diaphragm fixing member that fixes the fixing portions 3b and 3c of the speaker diaphragm 3 to the magnetic circuit 10 may be formed integrally with a horn located on the front side of the diaphragm portion 3a. Moreover, you may connect the components comprised separately.

  In addition, the speaker diaphragms of Examples 1 to 5 described above are cases of the ring diaphragm 3 including the outer peripheral edge portion 3d and the inner peripheral edge portion 3e on the outer periphery and inner periphery of the diaphragm portion 3a, respectively. The speaker diaphragm is a dome-shaped diaphragm including a fixed portion fixed to the magnetic circuit on the outer periphery of the dome-shaped diaphragm portion 3a, and an edge portion defined between the diaphragm portion and the fixed portion. May be. In the case of a speaker diaphragm that is integrally molded by hot press molding using a plain woven fabric coated with a thermoplastic resin as a base material, the second laminated structure that constitutes the edge portion is flattened when the coated thermoplastic resin melts. By entering into the gap between the warp and weft constituting the woven fabric and curing, the thin film is formed as compared with the first laminated structure constituting the diaphragm part and the fixed part. Similar to the ring type speaker, the reproduction frequency band of the dome type speaker can be widened, and the acoustic characteristics can be improved.

  The speaker diaphragm of the present invention is not limited to a tweeter for high-frequency range reproduction, and can also be applied to full-range speakers and other speakers for medium-low range reproduction.

It is a figure explaining the ring type speaker 1 by preferable embodiment of this invention. (Example 1) It is a figure explaining the ring diaphragm 3 of the ring type speaker 1 by preferable embodiment of this invention, and the voice coil 4 connected with this. (Example 1) It is an enlarged photograph explaining the mode of the cloth | dough surface of the ring diaphragm 3 of Example 1 by preferable embodiment of this invention. (Example 1) It is a figure explaining the ring diaphragm 30 of a prior art example, and the voice coil 4 connected with this. (Comparative Example 1) It is an enlarged photograph explaining the mode of the cloth surface of ring diaphragm 3 of Example 1. (Comparative Example 1) It is a graph showing the 1-m sound pressure frequency characteristic on the axis | shaft of the ring type speaker of this invention. (Examples 1-4) It is a graph showing the 1-m sound pressure frequency characteristic on an axis | shaft of the conventional ring type speaker. (Comparative Examples 1 and 2) It is a graph which shows the level of the harmonic distortion of the ring type speaker of the present invention. (Example 1, Example 6)

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Ring type speaker 2 Equalizer 3 Ring diaphragm 4 Voice coil 5 Bobbin 6 Coil 10 Magnetic circuit 11 Yoke 12 Magnet 13 Plate 20 Radiation hole 21 Inner peripheral part 22 Outer peripheral part 23 Connection arm part

Claims (10)

A speaker diaphragm formed integrally by hot press molding using a plain woven cloth coated with a thermoplastic resin as a base material,
A diaphragm part to which the voice coil is connected; a fixing part fixed to the magnetic circuit or the diaphragm fixing member; and an edge part defined between the diaphragm part and the fixing part,
The second laminated structure constituting the edge portion is melted into the gap between the warp and weft constituting the plain woven fabric by melting the coated thermoplastic resin, and is cured to constitute the diaphragm portion and the fixing portion. It is formed in a thin wall shape as compared with one laminated structure,
Speaker diaphragm. On the surface of the thermoplastic resin coated on the base material, further has a metal film, and an oxide film formed on the metal film,
The speaker diaphragm according to claim 1. The thickness t2 of the second laminated structure constituting the edge part is set within a range of 50% to 80% of the thickness t1 of the first laminated structure constituting the diaphragm part and the fixed part,
The rigidity G2 of the second laminated structure is small compared to the rigidity G1 of the first laminated structure, and the internal loss tan δ2 of the second laminated structure is large compared to the internal loss tan δ1 of the first laminated structure.
The speaker diaphragm according to claim 1 or 2. The warp yarns and the weft yarns constituting the plain woven fabric as the base material are selected from polyester of synthetic fibers, polyurethane, polyimide, and monofilament yarn of rayon,
The thermoplastic resin is selected from any one of synthetic resin polyethylene resin, acrylic resin, and urethane resin,
The speaker diaphragm according to any one of claims 1 to 3. The metal forming the metal film is selected from titanium, chromium, and gold.
The speaker diaphragm according to any one of claims 2 to 4. The metal film is formed by physical vapor deposition,
The oxide film is formed by an aging method,
The speaker diaphragm according to any one of claims 2 to 5. The thermoplastic resin further includes foam beads.
The speaker diaphragm according to any one of claims 1 to 6. The diaphragm part is an annular ring diaphragm part, and the fixing part fixes an inner periphery fixing part for fixing an inner periphery side of the ring diaphragm part and an outer periphery side of the ring diaphragm part. An outer peripheral fixing portion that includes an inner peripheral edge portion defined between the ring diaphragm portion and the inner peripheral fixing portion, and the ring diaphragm portion and the outer peripheral fixing portion. Including an outer peripheral edge portion defined between,
The speaker diaphragm according to any one of claims 1 to 7. The speaker diaphragm according to any one of claims 1 to 7,
A magnetic circuit, and a voice coil arranged in a magnetic gap of the magnetic circuit and connected to the speaker diaphragm,
Electrodynamic type speaker. A speaker diaphragm including the ring diaphragm according to claim 8;
A magnetic circuit; an equalizer coupled to the magnetic circuit; and a voice coil disposed in a magnetic gap of the magnetic circuit and coupled to the speaker diaphragm.
Electrodynamic type speaker.