JP5254119B2 - speaker - Google Patents

Description

  The present invention relates to a speaker using a diaphragm that is lightweight, has high rigidity, and has a wide piston vibration band, and in particular, a first diaphragm disposed on the front surface side that emits sound waves, and a rear surface side of the first diaphragm. The present invention relates to a speaker having a speaker vibration system having a double diaphragm structure including a second diaphragm to be connected, and a voice coil bobbin connected to the first diaphragm and the second diaphragm.

  In a speaker, an assembly structure is often used in which an inner peripheral end of a speaker diaphragm (particularly, a cone diaphragm) is bonded to a cylindrical side surface of a cylindrical voice coil bobbin with an adhesive. Some conventional speakers try to reduce the number of assembly steps by devising this assembly structure. In addition, in a speaker equipped with a cone-shaped diaphragm or dome-shaped diaphragm, a double vibration that improves the strength of the speaker vibration system by providing a cone-shaped diaphragm behind the diaphragm exposed on the front side. A plate structure may be adopted.

  Conventionally, for example, in a speaker in which a central portion of a diaphragm is coupled to a voice coil fitted into a magnetic gap of a magnetic circuit, the diaphragm has two or more different half apex angles or curvatures. There is a speaker characterized in that it is configured by using a cone (Patent Document 1). Further, as a speaker having a double diaphragm structure by the applicant of the present invention, the outer peripheral portions of two cone-shaped diaphragm bases having different half apex angles are bonded to each other, and the inner periphery of a common edge member And the inner peripheral portion of each of the diaphragm base members is coupled to a bobbin of a common voice coil with a gap therebetween, and a core material is disposed in the gap between the two diaphragm base members. There is a speaker characterized in that a diaphragm having a filled structure is held on a frame through the edge (Patent Document 2).

  Further, in a reverse dome type speaker in which the diaphragm shape is a front longitudinal section and the curved surface projects downward in a dome shape, the diaphragm 1 is formed by injection molding using a thermoplastic resin as a main material, and concentric circles are formed on the back surface of the diaphragm 1. A plurality of ring-shaped ribs 15a, 15b, 15c, 15d are provided, the voice coil bobbin 2 is fixed to the diaphragm 1 using one of the rib groups 15 as a guide, and the voice coil bobbin 2 There is a speaker in which a ring-shaped throat 22 is disposed between the rib group 15 and another rib of the rib group 15 (Patent Document 3).

  The speaker diaphragm not having the double diaphragm structure by the applicant of the present invention includes a first diaphragm part 5, a second diaphragm part 6 integrally formed with the first diaphragm part 5, and a first vibration. The first diaphragm portion 5 and the second diaphragm portion 6 are provided with an attachment portion 7 that protrudes on the back side of the coupling portion between the plate portion 5 and the second diaphragm portion 6 and to which one end of the voice coil bobbin is attached. The base material is impregnated with a thermosetting resin, and the mounting portion 7 is formed by curing the thermosetting resin (Patent Document 4). There is also a speaker diaphragm having a base and a surface material that is disposed on one side of the base and includes a woven fabric of polyethylene naphthalate fiber (Patent Document 5). These speaker diaphragms reduce the transmission loss of the driving force from the voice coil bobbin, and in the latter case, in particular, realize a speaker diaphragm with an excellent balance between Young's modulus and internal loss. Can improve the S / N ratio.

JP 63-155900 A (FIG. 1) Japanese Utility Model Publication No. 62-68394 (FIGS. 1 to 3) JP-A-9-247771 (FIG. 3) Japanese Patent No. 3846497 (FIGS. 1 to 4) JP 2007-259261 A

  However, a conventional speaker vibration system having a double diaphragm structure is not sufficient. By providing the first diaphragm on the front side and the second diaphragm on the back side, the speaker vibration system having a double diaphragm structure, which tends to be heavy, generally increases the reproduction efficiency of the speaker. It is necessary to reduce the weight. If the front diaphragm 1st diaphragm and the rear diaphragm 2 are not optimally designed, the speaker diaphragm system with a double diaphragm structure will have its own diaphragm if the weight is reduced and the rigidity is insufficient. There is a problem that the influence of the divided vibration mode at the frequency appears at a low frequency. That is, the speaker vibration system having a double diaphragm structure including the first diaphragm and the second diaphragm including the bobbin of the voice coil has a peak in the sound pressure frequency characteristics when the rigidity of the coupled structure is lowered. There is a problem that the dip becomes large and the piston vibration region becomes narrow, which may cause a decrease in reproduction sound quality.

  The present invention has been made to solve the above-described problems of the prior art, and its purpose is to connect the first diaphragm, the second diaphragm, and the bobbin of the voice coil that constitute the vibration system. It is an object of the present invention to provide a speaker having excellent reproduction sound quality with high rigidity of a speaker vibration system having a double diaphragm structure and less peak dip in sound pressure frequency characteristics.

The speaker of the present invention has a substantially cone-shaped first diaphragm disposed on the front side that emits sound waves, and is disposed on the rear side of the first diaphragm and is connected to the outer peripheral side of the first diaphragm on the outer peripheral side thereof. A substantially cone-shaped second diaphragm, a voice coil including a substantially cylindrical bobbin that is connected to the inner peripheral sides of the first diaphragm and the second diaphragm, and an outer peripheral part that is connected to the frame; An edge having an inner peripheral part connected to the outer peripheral side of the first diaphragm or the second diaphragm and a support movable part defined between the outer peripheral part and the inner peripheral part , the first diaphragm being A second diaphragm that has an engagement flange portion that extends from the outer peripheral end portion, defines a convex ridge line portion on the front surface side, and defines an engagement concave portion on the back surface side of the ridge line portion. but it has a engaging portion that engages the engaging recess of the first diaphragm at its outer peripheral end portion, edge, the first diaphragm The outer peripheral edge portion of the second diaphragm, which is defined as the portion to which the inner peripheral portion of the edge is connected, has an annular recess that engages with the joint portion, and the second diaphragm A separation space in which a separation distance increases from the engagement portion toward the inner peripheral side is formed, and an engagement recess portion of the first diaphragm and an engagement portion of the second diaphragm engaged with the engagement recess portion are The second adhesive different from the first adhesive is connected to the engagement recess or the first adhesive applied to the engagement portion and is separated from the first diaphragm by a separation space defined between the first diaphragm and the second diaphragm. Is applied and filled .

  More preferably, in the speaker of the present invention, the first diaphragm is connected to the inner peripheral side of the substantially cone-shaped base, the connecting part connected to the end of the bobbin, the center part covering the inner peripheral side of the connecting part, Is formed integrally with the base body.

  Preferably, the speaker of the present invention has a damper in which an inner peripheral end of the speaker is connected to a bobbin of a voice coil, a frame in which an outer peripheral portion of the edge and an outer peripheral end of the damper are connected, and a frame. And a magnetic circuit having a magnetic gap in which the coil of the coil is disposed.

  The operation of the present invention will be described below.

  The speaker of the present invention has a substantially cone-shaped first diaphragm disposed on the front side that emits sound waves, and is disposed on the rear side of the first diaphragm and is connected to the outer peripheral side of the first diaphragm on the outer peripheral side thereof. A substantially cone-shaped second diaphragm, and a voice coil including a substantially cylindrical bobbin in which the inner peripheral sides of the first diaphragm and the second diaphragm are connected to be separated from each other. Preferably, the speaker of the present invention is defined between an outer peripheral portion connected to the frame, an inner peripheral portion connected to the outer peripheral side of the first diaphragm or the second diaphragm, and the outer peripheral portion and the inner peripheral portion. A movable movable part, an edge having an inner peripheral end connected to the bobbin of the voice coil, a frame to which the outer peripheral part of the edge and the outer peripheral end of the damper are connected, and the frame are connected, And a magnetic circuit having a magnetic gap in which the coil of the voice coil is disposed. Therefore, the speaker of the present invention is an electrodynamic type speaker having a speaker vibration system having a double diaphragm structure.

  The first diaphragm has an engagement flange portion that extends so as to be folded back from the outer peripheral end portion thereof, defines a convex ridge line portion on the front surface side, and defines an engagement concave portion on the back surface side of the ridge line portion. The engagement flange portion of the first diaphragm increases the strength on the outer peripheral side of the first diaphragm and engages with the annular recess of the edge. Further, the second diaphragm has an engaging portion that engages with an engaging recess of the first diaphragm at an outer peripheral end portion thereof, and the first diaphragm and the second vibration are applied by the first adhesive applied thereto. The board is connected. Therefore, since the first diaphragm and the second diaphragm are separated from each other on the inner peripheral side and connected to the bobbin of the substantially cylindrical voice coil, a speaker vibration system is formed that has a solid structure with a substantially triangular cross section. To do. The first diaphragm is formed by integrally forming a connecting portion connected to the end of the bobbin and a central portion covering the inner peripheral side of the connecting portion on the inner peripheral side of the substantially cone-shaped base. Or a dome shape integrated with a dust cap.

  Here, the frequency f2 of the lowest order mode in which the outer peripheral side of the second diaphragm splits and vibrates is set higher than the frequency f1 of the lowest order mode in which the outer periphery of the first diaphragm splits and vibrates. The diaphragm is higher in rigidity than the first diaphragm. Further, the Young's modulus E2 of the second diaphragm is smaller than the Young's modulus E1 of the first diaphragm, or the internal loss δ2 of the second diaphragm is smaller than the internal loss δ1 of the first diaphragm. The specific gravity ρ2 of the second diaphragm is set to be large or smaller than the specific gravity ρ1 of the first diaphragm. Specifically, the first diaphragm is a speaker diaphragm in which a base is formed by impregnating a base material including a woven or nonwoven fabric made of fibers with a thermosetting resin containing an unsaturated polyester resin, or a paper A speaker diaphragm in which a substrate based on a paper material formed by making fibers is formed, and preferably a silk fiber made of any of plain weave, twill (oblique), satin (weaver), or A surface material including a woven fabric of polyethylene naphthalate fiber is further provided on the front side. The second diaphragm is a speaker diaphragm in which a base body made of a paper material formed by making paper fibers is formed.

  In the speaker vibration system having a double diaphragm structure according to the present invention, the second diaphragm is provided between the first diaphragm and the outer peripheral edge of the second diaphragm defined as a portion where the inner circumference of the edge is connected. A separation space is formed in which the separation distance increases from the engagement portion toward the inner peripheral side. By providing this separation space, the outer peripheral side of the first diaphragm that emits sound waves on the front side is reinforced by the outer peripheral side of the stronger second diaphragm having a higher frequency of split vibration than the first diaphragm. The piston vibration area can be expanded by increasing the frequency of the mode in which the outer peripheral side starts split vibration to a higher frequency. Further, when the second adhesive different from the first adhesive is applied and filled in the separation space defined between the first diaphragm and the second diaphragm, the inner space is relatively soft and the inner space is relatively soft. Since the second adhesive having a large loss suppresses the divided vibration of the first diaphragm and the second diaphragm, it is possible to realize a speaker with excellent reproduction sound quality with less peak dip on the sound pressure frequency characteristics.

  The loudspeaker of the present invention can provide a loudspeaker excellent in reproduction sound quality in which the loudspeaker vibration system having a double diaphragm structure has high rigidity, and there is little peak dip in the sound pressure frequency characteristics.

It is a figure explaining the speaker 1 by preferable embodiment of this invention. Example 1 It is a principal part enlarged view explaining the speaker vibration system of the speaker 1 of this invention. Example 1 It is a principal part enlarged view explaining the speaker vibration system of the speaker 100 of a comparative example. (Comparative example) It is a graph explaining the speaker diaphragm outer periphery intensity | strength of the speaker 1 of this invention, and the speaker 100 of a comparative example. (Example 1, Comparative Example 1) It is a graph explaining the acoustic characteristic of the speaker 1 of this invention, and the speaker 100 of a comparative example. (Example 1, Comparative Example 1) It is a principal part enlarged view explaining the speaker vibration system of the speaker 21 of the other Example of this invention. (Example 2) It is a principal part enlarged view explaining the speaker vibration system of the speaker 22 of the other Example of this invention. (Example 3) It is a principal part enlarged view explaining the speaker vibration system of the speaker 23 of the other Example of this invention. Example 4 It is a figure explaining the speaker 31 by other preferable embodiment of this invention. (Example 5) It is a figure explaining the speaker 41 by other preferable embodiment of this invention. (Example 6)

  Hereinafter, although the speaker by preferable embodiment of this invention is demonstrated, this invention is not limited to these embodiment.

  FIG. 1 is a schematic cross-sectional view of a speaker 1 according to a preferred embodiment of the present invention. 2 is an enlarged view of a main part for explaining a speaker vibration system of the speaker 1, and is an enlarged cross-sectional view of a portion X shown in FIG. In addition, as will be described later, a part of the structure of the speaker 1, an internal structure, and the like are omitted. In the speaker 1, the upper side in the figure where the speaker diaphragm 5 as the first diaphragm is exposed is the front side, and the lower side in the figure where the magnetic circuit 10 is attached is the back side.

  The speaker 1 is an electrodynamic speaker having a bullet-shaped equalizer 9 and a caliber of about 15 cm. The speaker 1 has a substantially cone-shaped first diaphragm 5 disposed on the front side that emits sound waves, and a first diaphragm. 5 is arranged on the back side of the first diaphragm 5 and is connected to the outer peripheral side of the first diaphragm 5 on the outer peripheral side thereof, and the inner peripheral side of the first diaphragm 5 and the second diaphragm 6 is respectively connected to the outer peripheral side of the first diaphragm 5. The voice coil bobbin 2 having a substantially cylindrical shape that is connected to be separated from each other and the voice coil 3 wound around the lower end of the voice coil bobbin 2 constitute a speaker vibration system having a double diaphragm structure. The voice coil bobbin 2 and the voice coil 3 are arranged in a magnetic gap of a magnetic circuit 10 fixed to the frame 8, and are displaced in the magnetic gap in accordance with an input signal, whereby a speaker having a double diaphragm structure of the speaker 1 is provided. Drive the vibration system. The speaker vibration system of the double diaphragm structure of the speaker 1 is supported by a damper 4 and an edge 7 fixed to the frame 8 so as to vibrate in the vertical direction shown in the figure.

  The voice coil bobbin 2 is made of, for example, aluminum having a thickness of 0.05 mm. The voice coil 3 is wound around the lower end of the voice coil bobbin 2, and reinforcing paper is wound on the outer curved surface where the voice coil 3 is not wound. As a whole, it is formed into a cylindrical shape having a diameter of about 39.0 mm. In addition, the voice coil bobbin 2 may be formed of a polyimide film, duralumin, sinter, capton, or the like. A tinsel wire (not shown) is soldered and fixed to the voice coil 3, and the other end of the tinsel wire is fixed so as to be electrically connected to a terminal (not shown) fixed to the frame 8. A voice signal current is supplied to the voice coil 3 through these terminals and the tinsel wire.

  An inner diameter end of the damper 4 is connected to the outer curved surface of the voice coil bobbin 2 with an adhesive. The outer diameter end of the damper 4 is bonded and fixed to a damper fixing portion of the frame 8. The damper 4 may be an annular corrugation damper that is formed by impregnating a resin such as a phenol resin with a woven fabric of flexible fibers as a base material, and is made of another material. Also good. For example, a butterfly damper having an arm connecting the inner ring and the outer ring and formed of metal or resin may be used. The frame 8 is an aluminum die-cast frame formed in a basket shape, and is connected to the magnetic circuit 10 by a plurality of screws. The frame 8 may be an iron plate frame press-molded in a basket shape corresponding to a speaker vibration system having a double diaphragm structure.

  The magnetic circuit 10 includes an annular top plate 11 fixed to the frame 8, a cylindrical pole having a center pole inserted into a circular hole formed in the center of the top plate 11 and a flat plate-like under plate. 12 and an annular magnet 13. The top plate 11 and the pole 12 form a circular magnetic gap having a uniform width. The magnet 13 is bonded so as to be sandwiched between the top plate 11 and the under plate of the pole 12. The magnet 13 of the present embodiment is a ferrite magnet, and may be a Nd—Fe—B rare earth magnet having a larger residual magnetization and coercive force, and having a small volume and a strong coercive force. The magnetic circuit 10 of this embodiment includes a cancel magnet 14 that is magnetized and connected to the back side of the under plate of the pole 12 so as to have a magnetic polarity opposite to the magnet 13, and from the back side of the cancel magnet 14. And a cover 15 that magnetically shields the entire magnetic circuit 10.

  In this embodiment, the equalizer 9 is a shell-shaped member formed of an alloy containing aluminum, and the equalizer 9 is formed on the center pole of the pole 12 of the magnetic circuit 10 so that the pointed tip side protrudes from the neck portion of the first diaphragm 5. Connected and fixed. The equalizer 9 fills the cylindrical internal space formed by the voice coil bobbin 2 and a part of the space surrounded by the substantially cone-shaped first diaphragm 5 to eliminate air occupying these spaces and to adjust the directivity characteristics. To flatten the sound pressure frequency characteristics. The equalizer 9 connected to the magnetic circuit 10 is preferably formed of a nonmagnetic member such as brass or resin.

  The first diaphragm 5 is a diaphragm that is exposed to the front side when the speaker 1 having a speaker vibration system having a double diaphragm structure is viewed from the front, and is substantially defined by a curve whose cross-sectional shape is smoothly continuous. The diaphragm is a cone-shaped diaphragm, and has a substantially cone-shaped diaphragm portion 5a and an engagement flange portion 5b extending so as to be folded back from the outer peripheral end portion. The diaphragm portion 5a having a substantially cone shape has an inner diameter of about 39.5 mm, an outer diameter of about 113.5 mm, and a height of about 26.8 mm. As shown in FIG. 2, the engagement flange 5b having a length of about 1.5 mm defines a convex ridge line part 5c on the front side and an engagement concave part 5d on the back side of the ridge line part 5c. To do. The inner diameter end of the first diaphragm 5 is connected to the outer curved surface of the voice coil bobbin 2 with an acrylic adhesive.

  The first diaphragm 5 of this embodiment is a base (diaphragm portion 5a) formed by impregnating a thermosetting resin into a base material that is a laminate including a woven fabric layer or a nonwoven fabric layer made of inorganic fibers or natural fibers. , An engagement flange portion 5b, a ridge line portion 5c, and an engagement recess portion 5d), and a surface material 5e bonded to the front side of the base body. Specifically, the substrate is obtained by laminating two layers of technola fiber nonwoven fabric, impregnating with an unsaturated polyester resin, and performing hot press molding. Since unsaturated polyester has a high curing rate and a low curing temperature, a substrate can be produced by hot press molding in a short time. Further, the surface material 5e is obtained by applying a thermoplastic adhesive to the substrate and drying it, along with a woven silk fiber woven fabric, and heat-pressing them to integrate them. The woven fabric of cocoon silk fibers forming the surface material 5e has silk raw yarns of warp yarns 21 / 2d 129 yarns / cm and weft yarns 21 / 2d 53 yarns / cm, and the constituent ratio of warp yarns and weft yarns is 2. 43, 2 jumps and 5 pieces of lion weave.

As a result, the first diaphragm 5 of the present embodiment has the following physical properties, and the frequency f1 of the lowest mode in which the outer peripheral side of the single first diaphragm 5 divides and vibrates is set to about 3.5 kHz. ing.
(Example 1): First diaphragm 5
Thickness t1 0.3mm
Weight 3.8g
428 g / m ²
Young's modulus E11 (longitudinal direction) 6.4E + 9Pa
Young's modulus E12 (weft direction) 5.5E + 9Pa
Internal loss tan δ1 0.1
Density (specific gravity) ρ1 1.2 g / cm ³

  The second diaphragm 6 is a diaphragm that is hidden on the back side when the speaker 1 having a speaker vibration system having a double diaphragm structure is viewed from the front, and the first diaphragm 5 having a smoothly continuous cross-sectional shape. 2 is a substantially cone-shaped diaphragm defined by an R curve and a straight line different from each other. As shown in FIG. 2, a substantially cone-shaped diaphragm portion 6a and an outer peripheral end of the first diaphragm 5 And an engaging portion 6b that engages with the engaging recess 5d. The diaphragm portion 6a having a substantially cone shape has an inner diameter of about 39.5 mm, an outer diameter of about 111.5 mm, and a height of about 31.2 mm. The inner diameter end of the second diaphragm 6 is connected to the outer curved surface of the voice coil bobbin 2 so as to be separated from the inner diameter end of the first diaphragm 5 by an acrylic adhesive.

  The second diaphragm 6 of the present embodiment has a paper base formed by paper making, and a plurality of through holes are concentrically formed in the vicinity of the inner peripheral end of the diaphragm portion 6a. Is formed. The Young's modulus E2 of the second diaphragm 6 is smaller than the Young's modulus E11 or E12 of the first diaphragm 5, and the internal loss δ2 of the second diaphragm 6 is the internal loss δ1 of the first diaphragm 5. The specific gravity ρ2 of the second diaphragm 6 is set to be smaller than the specific gravity ρ1 of the first diaphragm 5.

As a result, the second diaphragm 6 of the present embodiment has the following physical properties, and the frequency f2 of the lowest mode in which the outer peripheral side of the single second diaphragm 6 vibrates separately is set to about 4.0 kHz. ing.
(Example 1): 2nd diaphragm 6
Thickness t2 0.5mm
Weight 2.2g
Weight per unit area 257 g / m ²
Young's modulus E2 2.37E + 9Pa
Internal loss tan δ2 0.02
Density (specific gravity) ρ2 0.5 g / cm ³

  The edge 7 is a ring-shaped or ring-shaped corrugation edge that supports the vibration system of the speaker having a double diaphragm structure so as to vibrate, and an outer peripheral portion 7a that is bonded and fixed to the edge fixing portion of the frame 8. The inner peripheral part 7b connected to the outer peripheral side of the second diaphragm 6 from the back side, the support movable part 7c forming a corrugation between the outer peripheral part 7a and the inner peripheral part 7b, and the most corrugation of the support movable part 7c An annular recess 7d that engages with the engagement flange 5b of the first diaphragm 5 from the front side is provided on the inner peripheral side. The edge 7 of the present embodiment is formed by pressurizing and heating a suede-like artificial leather made of polyester super fine fibers having flexibility, and a paper gasket 7e is bonded to the front side of the outer peripheral portion 7a. ing. In addition, the support movable part 7c of the edge 7 of a present Example has a corrugation by which the height of the peak part which becomes convex ahead becomes small as it goes to an inner peripheral side from an outer peripheral side.

  As shown in FIG. 2, an engagement flange 5 b including a base material or a thermosetting resin is formed on the outer peripheral end of the diaphragm portion 5 a of the first diaphragm 5. The engaging flange portion 5b functions as a rib that reinforces the diaphragm portion 5a at the outer peripheral side end portion of the diaphragm portion 5a and increases the strength on the outer peripheral side, and on the side opposite to the substantially cone shape of the diaphragm portion 5a. Since it is formed as a folded back portion, a convex ridge line portion 5c is defined on the front side, and an engagement concave portion 5d is defined on the back side of the ridge line portion 5c. In the case of the speaker 1 of the present embodiment, the second diaphragm 6 has an engaging portion 6b that engages with the engaging recess 5d of the first diaphragm 5 at the outer peripheral end thereof, and the edge 7 Since the inner peripheral portion 7b of the first diaphragm 5 is bonded and fixed, the engagement flange portion 5b of the first diaphragm 5 engages with the annular concave portion 7d of the support movable portion 7c formed by the corrugation of the edge 7.

  That is, in the speaker 1 of the present embodiment, in the step of bonding the outer peripheral end portion of the first diaphragm 5 to the vibration system formed by the second diaphragm 6 and the edge 7, the engagement flange portion 5 b of the first diaphragm 5. Is engaged with the annular recess 5d formed by the corrugation of the edge 7, the first diaphragm 5 can be bonded to the voice coil bobbin 2 and the second diaphragm 6 without tilting. Since the 2nd diaphragm 6 has the engaging part 6b engaged with the engagement recessed part 5d of the 1st diaphragm 5 in the outer peripheral edge part, if 1st adhesive agent Ad1 is apply | coated here, the 1st diaphragm 5 will be provided. Are connected to the second diaphragm 6. As shown in FIG. 1, the first diaphragm 5 and the second diaphragm 6 are connected to the substantially cylindrical voice coil bobbin 2 with their inner peripheral sides separated from each other. This constitutes a speaker vibration system having a double diaphragm structure.

  Further, in the speaker vibration system of the double diaphragm structure of the speaker 1 of the present embodiment, the outer peripheral edge portion of the second diaphragm 6 defined as the portion where the inner peripheral portion 7b of the edge 7 is connected is the first diaphragm. 5, a separation space Y is formed in which the separation distance increases from the engagement portion 6 b of the second diaphragm 6 toward the inner peripheral side. As shown in FIG. 2, the separation space Y is a triangular space having a sharp cross section defined between the back surface of the first diaphragm 5 and the front surface of the second diaphragm 6. By providing this separation space Y, the outer peripheral side of the first diaphragm 5 that radiates sound waves on the front side is reinforced by the outer peripheral side of the stronger second diaphragm 6 that has a higher frequency of split vibration than the first diaphragm 5. The structure to do is realized.

  In this embodiment, the first adhesive Ad1 applied to the engaging recess 5d of the first diaphragm 5 and the engaging portion 6b of the second diaphragm 6 engaged therewith is a rubber adhesive. Yes, after the adhesive is cured, the Young's modulus is relatively large, the hardness is large and hard, and the internal loss is small. In the case of the present embodiment, the second adhesive Ad2 different from the first adhesive Ad1 is applied to the separation space Y defined between the first diaphragm 5 and the second diaphragm 6. Filled. The second adhesive Ad2 is an acrylic resin emulsion adhesive, and is an adhesive having a relatively small Young's modulus, a low hardness, and a low internal loss after the adhesive is cured. For example, the first adhesive Ad1 in this example has a Young's modulus of 7.3E + 8 Pa after the adhesive is cured, and an internal loss of 0.161 after the adhesive is cured. It is a type A durometer according to K 6253 and has a hardness of about 27 points. On the other hand, the second adhesive Ad2 has a Young's modulus of 6.5E + 7 Pa after the adhesive is cured, an internal loss of 0.30 after the adhesive is cured, and a hardness of about 8 points. . That is, the first adhesive Ad1 is an adhesive that is relatively harder than the second adhesive Ad2. The first adhesive Ad1 and the second adhesive Ad2 are preferably applied separately so as not to mix.

  FIG. 3 is an enlarged view of a main part for explaining the speaker vibration system of the speaker 100 of the comparative example. The speaker 100 of the comparative example is an electrodynamic type speaker in which the portion illustrated as an enlarged cross-sectional view in FIG. 3 has a speaker vibration system having a double diaphragm structure different from the speaker 1 of the present embodiment. The speaker vibration system of the speaker 100 of the comparative example includes a first diaphragm 50, a second diaphragm 60, and an edge 70. Therefore, illustration and description of the common voice coil bobbin 2, voice coil 3, damper 4, frame 8, equalizer 9, and magnetic circuit 10 are omitted.

  The first diaphragm 50 is a diaphragm that is exposed to the front side when the speaker 100 of the comparative example is viewed from the front, and is a diaphragm having a substantially cone shape that is defined by a curved line whose cross-sectional shape is smoothly continuous. It has a substantially cone-shaped diaphragm portion 50a and an engaging flange portion 50b extending so as to be folded back from the outer peripheral end portion. The engagement flange portion 50b defines a convex ridge line portion 50c on the front surface side, and defines an engagement concave portion 50d on the back surface side of the ridge line portion 50c. The inner diameter end of the first diaphragm 50 is connected to the outer curved surface of the voice coil bobbin 2 with an adhesive. Moreover, the 1st diaphragm 50 is a base material which is a laminated body containing the woven fabric layer or nonwoven fabric layer which consists of an inorganic fiber or a natural fiber like the 1st diaphragm 5 of the previous Example, and a thermosetting resin is applied to it. A substrate formed by impregnation and a surface material 50e bonded to the front side of the substrate are obtained. Two layers of non-woven fabrics of technola fibers are laminated, impregnated with an unsaturated polyester resin, and obtained by hot press molding. .

  The second diaphragm 60 is a diaphragm that is hidden on the back side when the speaker 100 of the comparative example is viewed from the front, and is defined by an R curve and a straight line that are different from the first diaphragm 50 having a smoothly continuous cross-sectional shape. As shown in FIG. 3, the substantially cone-shaped diaphragm portion 60a and the engagement of engaging with the engaging recess 50d of the first diaphragm 50 at the outer peripheral end of the diaphragm portion 60a. Part 60b. The inner diameter end of the second diaphragm 60 is connected to the outer curved surface of the voice coil bobbin 2 so as to be separated from the inner diameter end of the first diaphragm 50 by an adhesive. The second diaphragm 60 has a paper base formed by paper making.

  The edge 70 is an annular corrugation edge that supports a speaker vibration system having a double diaphragm structure so as to vibrate. The edge 70 is bonded and fixed to the edge fixing portion of the frame 8, and the second diaphragm 60. An inner peripheral portion 70b connected to the outer peripheral side from the back side, a support movable portion 70c forming a corrugation between the outer peripheral portion 70a and the inner peripheral portion 70b, and a front surface on the innermost peripheral side of the corrugation of the support movable portion 70c. And an annular recess 70d with which the engagement flange 50b of the first diaphragm 50 is engaged from the side. The edge 70 of the comparative example is formed by pressurizing and heating a suede-like artificial leather made of polyester super-fine fibers having flexibility, and a paper gasket 70e is bonded to the front side of the outer peripheral portion 70a. Yes. In addition, the support movable part 70c of the edge 70 of the comparative example has a corrugation in which the height of the peak portion that is convex forward is changed from the outer peripheral side toward the inner peripheral side.

  However, in the speaker vibration system having the double diaphragm structure of the speaker 100 of the comparative example, the outer peripheral edge portion of the second diaphragm 60 defined as the portion where the inner peripheral portion 70 b of the edge 70 is connected is the first diaphragm 50. And the first diaphragm 50 is not formed with a separation space Y as in the previous embodiment. That is, since the first diaphragm 50 and the second diaphragm 60 are in close contact with each other and connected, the inner peripheral portion 70b of the edge 70 is connected to the inner peripheral side of the outer peripheral edge portion of the second diaphragm 60. A space Y ′ as shown in FIG. 3 where the distance away from the engaging portion 60b of the second diaphragm 60 toward the inner peripheral side increases as it goes to the inner peripheral side is merely formed in the portion that is not present. In the speaker vibration system of the double diaphragm structure of the speaker 100 of the comparative example, although the material having the same configuration as the double diaphragm structure of the speaker 1 of the previous embodiment is used, the first diaphragm 50 and the first diaphragm 2 Since the shape is different so that the outer peripheral edge of the diaphragm 60 is in close contact with each other, the rigidity of this portion is insufficient and the shape is easily bent. That is, the outer peripheral edge approaches a flat surface, becomes heavier and splits and vibrates, and as a result, the piston vibration region is narrowed.

  FIG. 4 is a graph illustrating the speaker diaphragm outer peripheral strength of the speaker 1 of this embodiment and the speaker 100 of the comparative example. In the speaker vibration system having a double diaphragm structure constituted by the voice coil bobbin 2, the first diaphragm 5, and the second diaphragm 6, a point a0 shown in the cross-sectional view of FIG. 1 is fixed, and a static force of ± 5 kgf is fixed to the point a1. When the weight is applied, the horizontal axis of the graph of FIG. 3 indicates the absolute value of the static weight, and the vertical axis indicates the absolute value of the displacement. In the first embodiment, the UP is displaced upward, and the DOWN is displaced downward. The two loci are not greatly deviated, and vertical symmetry can be ensured. When these trajectories are averaged, the static load necessary to displace the point a1 of the speaker vibration system of the first embodiment by 1 mm while the point a0 is fixed is calculated to be about 52.0 kgf. On the other hand, in the case of the comparative example 100, the deviation between the two trajectories becomes large when displacing upward or downward, and the symmetry in the vertical direction is reduced. When these trajectories are averaged, the static load necessary to displace the point a1 of the speaker vibration system of Comparative Example 100 by 1 mm while the point a0 is fixed is calculated to be about 47.1 kgf. Compared to the case of Example 1, it is about 10.4% lower. Thus, the speaker vibration system of the speaker 1 of the present embodiment can increase the outer peripheral strength of the speaker diaphragm as compared with the conventional double diaphragm structure as in the comparative example 100.

  FIG. 5 is a graph illustrating the acoustic characteristics of the speaker 1 of the present embodiment and the speaker 100 of the comparative example. In the double diaphragm structure of the speaker 1 of the present embodiment, the frequency fh of the lowest order mode, which is the first mode in which the outer peripheral side starts split vibration, is about 4.2 kHz. The plate 5 and the second diaphragm 6 are in piston vibration. The speaker vibration system having a double diaphragm structure that forms the separation space Y of the speaker 1 according to the present embodiment has a frequency f1 in a mode in which the outer peripheral side of the first diaphragm 5 starts divided vibration, and the outer peripheral side starts higher divided vibration. The second diaphragm 6 having the mode frequency f2 can be pushed up to a higher frequency (about 4.2 kHz in this embodiment) to expand the piston vibration region. On the other hand, in the double diaphragm structure of the speaker 100 of the comparative example, the frequency fh of the first mode in which the outer peripheral side starts split vibration is about 3.2 kHz, and the first diaphragm 50 and the second diaphragm 60 are pistons. The vibrating area is narrow.

  In a speaker vibration system that does not have a general double diaphragm structure, there is a problem that if the cone shape is deepened or a highly rigid material is used, the resonance peak becomes sharp and large, and the speaker diaphragm is attenuated. In the case where the resonance peak is suppressed by using a material having a high rate, there is a problem that it is difficult to achieve both the rigidity and the sufficient piston regeneration band. In the speaker 1 having the speaker vibration system of the double diaphragm structure, the basic characteristics are mainly determined by the sound wave radiated from the first diaphragm 5, so that the region where the first diaphragm 5 vibrates the piston is expanded. It is preferable that the second diaphragm 6 is connected to the first and second diaphragms. At that time, since the upper limit of the piston region is determined by the frequency of the mode in which the outer peripheral side, which is the lowest order resonance mode of the first diaphragm 5, starts the divided vibration, it is desired to extend the frequency as high as possible.

  However, in the double diaphragm structure of the speaker 1 of the present embodiment, both of this high rigidity and a high damping rate can be achieved. The first diaphragm 5 is made of a material having rigidity capable of securing a sufficient piston regeneration band, and the second diaphragm 6 has a loss capable of sufficiently suppressing the mode in which the outer peripheral side of the first diaphragm 5 starts split vibration. It is preferable to use a lightweight material with a high internal loss value. The Young's modulus E2 of the second diaphragm 6 is smaller than the Young's modulus E1 of the first diaphragm 5, or the internal loss δ2 of the second diaphragm 6 is compared with the internal loss δ1 of the first diaphragm 5. Therefore, it is preferable that the specific gravity ρ2 of the second diaphragm 6 is smaller than the specific gravity ρ1 of the first diaphragm 5. Therefore, in the speaker 1 having a speaker vibration system having a double diaphragm structure, a diaphragm having a cone-shaped base body made of a paper material formed by forming paper fibers on the second diaphragm 6 is employed.

  In addition, the base material which comprises the base | substrate of the 1st diaphragm 5 can employ | adopt arbitrary appropriate woven fabrics or nonwoven fabrics, and arbitrary appropriate thermosetting resins according to a use and the objective. The base material may be a woven fabric or a non-woven fabric alone, or a laminate having a plurality of non-woven fabrics, or a laminate of a woven fabric and a non-woven fabric. Typical examples of the nonwoven fabric include para-type aramid fiber, meta-type aramid fiber, rayon fiber, cotton fiber, ultra-high strength polyethylene fiber, and polyarylate fiber. Examples of the woven fabric include polytrimethylene terephthalate and polyethylene naphthalate (PEN) fiber. The woven or non-woven fibers may be natural fibers or inorganic fibers as described above.

  Moreover, like the 1st diaphragm 5 of a present Example, the surface material 5e may be provided and it does not need to be provided. The surface material 5e is a plain weave, twill weave, satin weave, satin weave, satin weave having a composition ratio of warp and weft about 1.2 or more. If the woven fabric is any one of the above, the Young's modulus varies greatly with the circumstances, and the first diaphragm 5 including the surface material 5e tends to disperse the resonance frequency in the high region and flatten the sound pressure frequency characteristics. In terms of audibility, there is no tightness in the high frequency range, making it very easy to listen. The woven fabric having anisotropy that forms the surface material 5e is a twill (oblique) weave or satin (weaver) weave with a warp and weft component ratio of about 1.2 or more. If so, at least silk fiber (including silk raw silk and silk spun), cotton fiber, wool fiber, polyester fiber, polyethylene naphthalate fiber, nylon fiber, aramid fiber, acrylic fiber, polylactic acid fiber, glass fiber, carbon fiber It only needs to contain one fiber. In the case of satin weave, the warp is dense and the texture points are scattered sparsely compared to plain weave and twill weave, so a smooth and glossy appearance can be obtained. It is suitable for the surface material 5e of the first diaphragm 5 having a substantially cone shape.

  Further, in the speaker 1 of the present embodiment, the separation space Y defined between the first diaphragm 5 and the second diaphragm 6 constituting the double diaphragm structure is different from the first adhesive Ad1. 2 Since the adhesive Ad2 is applied and filled, the second adhesive Ad2 having a large internal loss suppresses the divided vibration of the first diaphragm 5 and the second diaphragm 6, and further the peak on the sound pressure frequency characteristic A speaker with excellent reproduction sound quality with less dip and less harmonic distortion can be realized. The first adhesive Ad1 and the second adhesive Ad2 have relatively different Young's modulus values after curing as well as constituent components, and also have different internal loss values. In order to increase the rigidity of the speaker vibration system having the double diaphragm structure of the present embodiment and suppress the divided vibration, the second adhesive Ad2 has a lower hardness after being relatively cured than the first adhesive Ad1. It is desirable that it is soft and has a small Young's modulus and a large internal loss.

  In the case of the present embodiment, the inner peripheral portion 7b of the edge 7 is bonded and connected to the outer peripheral side of the second diaphragm 6 from the back side. However, 7b of the edge 7 may be bonded so as to overlap the front side of the outer diameter end of the first diaphragm 5, and in this case, the engagement flange portion 5b of the first diaphragm 5 is supported and movable. It only needs to be engaged with the annular recess 7d of the portion 7c. The first diaphragm 5 can be bonded to the voice coil bobbin 2 and the second diaphragm 6 without tilting, and a speaker vibration system having a double diaphragm structure having sufficient rigidity can be realized.

  The speaker 1 of the present embodiment is an electrodynamic speaker that includes a bullet-shaped equalizer 9 and does not include a dust cap that covers the upper end side of the cylindrical voice coil bobbin 2, but is limited to such an embodiment. It is not something. When the bullet-shaped equalizer 9 is not provided, a dust cap connected to the voice coil bobbin 2 or the first diaphragm 5 may be provided.

  FIG. 6 is an enlarged view of a main part for explaining the speaker vibration system of the speaker 21 (not shown) according to another preferred embodiment. Similarly to the case of FIG. 2 of the previous example, the portion X shown in FIG. It is sectional drawing to which the part corresponded to was expanded. The speaker 21 is a common speaker, except that the configuration of the first diaphragm 5 constituting the double diaphragm structure is different from that of the previous embodiment as compared with the speaker 1 of the previous embodiment. Therefore, the description of the configuration of the common voice coil bobbin 2, the second diaphragm 6, and the edge 7 is omitted.

  As with the first diaphragm 5 of the previous embodiment, the first diaphragm 5 of this embodiment is thermosetting to a base material that is a laminate including a woven fabric layer or a nonwoven fabric layer made of inorganic fibers or natural fibers. A diaphragm including a substrate (including a diaphragm portion 5a, an engagement flange portion 5b, a ridge line portion 5c, and an engagement recess portion 5d) formed by impregnating a resin, and in the case of the previous embodiment, the front surface of the substrate This is a diaphragm in which the base is exposed to the front side, except that the surface material 5e bonded to the side is not provided. Specifically, the substrate is obtained by laminating a nonwoven fabric of technola fibers and a nonwoven fabric of cotton, impregnating with an unsaturated polyester resin, and performing hot press molding. The inner diameter end of the first diaphragm 5 is connected to the outer curved surface of the voice coil bobbin 2 with an acrylic adhesive.

As a result, the first diaphragm 5 of the present embodiment has the following physical properties, and the frequency f1 of the mode in which the outer peripheral side of the single first diaphragm 5 divides and vibrates is set to about 3.0 kHz. Since the first diaphragm 5 of the present embodiment does not include the surface material 5e, the first diaphragm 5 does not exhibit a remarkable anisotropy such that the Young's modulus varies greatly with the circumstances. However, since the first diaphragm 5 of the present embodiment can be reduced in weight by the amount not including the surface material 5e, the reproduction efficiency of the speaker 21 can be increased.
(Example 2): First diaphragm 5
Thickness t1 0.22mm
Weight 3.1g
349 g / m ²
Young's modulus E1 6.5E + 9Pa
Internal loss tan δ1 0.07
Density (specific gravity) ρ1 1.3 g / cm ³

  Further, the second diaphragm 6 of this embodiment is the same as that of the previous embodiment, and as a result, the Young's modulus E2 of the second diaphragm 6 is compared with the Young's modulus E1 of the first diaphragm 5. The internal loss δ2 of the second diaphragm 6 is large compared to the internal loss δ1 of the first diaphragm 5, and the specific gravity ρ2 of the second diaphragm 6 is compared to the specific gravity ρ1 of the first diaphragm 5. Satisfy the relationship set small.

  Further, the speaker vibration system of the double diaphragm structure of the speaker 21 of the present embodiment is the second diaphragm 6 that is defined as a portion to which the inner peripheral portion 7b of the edge 7 is connected, as in the previous embodiment. The outer peripheral edge portion of the first diaphragm 5 and the first diaphragm 5 form a separation space Y in which the distance of separation increases from the engagement portion 6b of the second diaphragm 6 toward the inner periphery. Therefore, by providing this separation space Y, the outer periphery of the first diaphragm 5 that radiates sound waves on the front side, the outer periphery of the second diaphragm 6 that has a higher frequency of dividing and vibrating than the first diaphragm 5 is higher. A structure in which the side is reinforced is realized.

  In the double diaphragm structure of the speaker 21 of the present embodiment, the frequency fh of the first mode in which the outer peripheral side starts split vibration is about 4.0 kHz, and the first diaphragm 5 and the second vibration are below that frequency. The plate 6 is in piston vibration. In the speaker vibration system having a double diaphragm structure that forms the separation space Y of the speaker 1 of the present embodiment, the frequency f1 of the lowest order mode at which the outer peripheral side of the first diaphragm 5 starts divided vibration and the outer peripheral side performs divided vibration. The second diaphragm 6 having a higher mode frequency f2 to be started can be pushed up to a higher frequency to expand the piston vibration region than before.

  As shown in FIG. 6, separately from the first adhesive Ad1, which is a rubber adhesive applied to the engaging recess 5d of the first diaphragm 5 and the engaging part 6b of the second diaphragm 6, The different second adhesive Ad2 may not necessarily be applied to the separation space Y defined between the first diaphragm 5 and the second diaphragm 6. Of course, as the second adhesive Ad2, it is the same acrylic resin emulsion adhesive as in the previous embodiment, the Young's modulus after the adhesive is cured is relatively small, soft and has a large internal loss, You may isolate | separate and apply | coat so that it may not mix with 1st adhesive agent Ad1.

  FIG. 7 is an enlarged view of a main part for explaining the speaker vibration system of the speaker 22 (not shown) according to another preferred embodiment. Similarly to the case of FIG. 2 of the previous example, the portion X shown in FIG. It is sectional drawing to which the part corresponded to was expanded. The speaker 22 is a common speaker as compared with the speaker 1 or 21 of the previous embodiment, except that the configuration of the first diaphragm 25 constituting the double diaphragm structure is different from that of the previous embodiment. . Therefore, the description of the configuration of the common voice coil bobbin 2, the second diaphragm 6, and the edge 7 is omitted.

  Unlike the first diaphragm 5 of the previous embodiment, the first diaphragm 25 of the present embodiment is a base (a diaphragm portion 25a, an engagement rod) made of a paper material formed by making paper fibers. Part 25b, a ridge part 25c, and an engagement recess 25d.) And a surface material 25e that is bonded to the front side of the substrate and exposed to the front side. The base of the first diaphragm 25 is a paper cone formed by paper making, press-dried, cut and molded, and is a paper material, except that it is a paper cone. The point provided with the part 25a, the engagement collar part 25b extended so that it may return | fold from the outer peripheral edge part, the convex ridgeline part 25c on the front side, and the engagement recessed part 25d on the back side of the ridgeline part 25c Match. Since the paper material is light, inexpensive, and low cost, the first diaphragm 25 can be realized at low cost.

  Further, the surface material 25e of the present embodiment uses a woven fabric of polyethylene naphthalate fiber different from the case of the surface material 5e included in the first diaphragm 5 of the first embodiment. The twill weave of polyethylene naphthalate fibers forming the surface material 25e has a warp 270d of 40 yarns / cm and a weft yarn of 270d 31 yarns / cm in a ratio of warp to weft of 1.29. / 2 twill weave. The surface material 25e is obtained by applying a thermoplastic adhesive to the base body and drying the twilled polyethylene fiber woven fabric together with a hot melt film, and hot-pressing them to form the first diaphragm 25. As one. The inner diameter end of the first diaphragm 25 is connected to the outer curved surface of the voice coil bobbin 2 with an acrylic adhesive as in the previous embodiment.

As a result, the first diaphragm 25 of the present embodiment has the following physical properties, and the frequency f1 of the mode in which the outer peripheral side of the single first diaphragm 25 divides and vibrates is set to about 2.8 Hz.
(Example 3): 1st diaphragm 25
Thickness t1 0.28mm
Weight 3.0g
338 g / m ²
Young's modulus E11 (longitudinal direction) 3.5E + 9Pa
Young's modulus E12 (weft direction) 3.1E + 9Pa
Internal loss tan δ1 0.15
Density (specific gravity) ρ1 1.0 g / cm ³

  Further, the second diaphragm 6 of this embodiment is the same as that of the previous embodiment, and as a result, the Young's modulus E2 of the second diaphragm 6 is equal to the Young's modulus E11 to E12 of the first diaphragm 25. The internal loss δ2 of the second diaphragm 6 is small compared to the internal loss δ1 of the first diaphragm 25, and the specific gravity ρ2 of the second diaphragm 6 is equal to the specific gravity ρ1 of the first diaphragm 25. Satisfying the relationship set to be smaller.

  Further, the speaker vibration system of the double diaphragm structure of the speaker 22 of the present embodiment is the second diaphragm 6 defined as a portion where the inner peripheral portion 7b of the edge 7 is connected, as in the previous embodiment. The outer peripheral edge portion of the first diaphragm 25 and the first diaphragm 25 form a separation space Y in which the distance away from the engagement portion 6b of the second diaphragm 6 increases toward the inner periphery. Therefore, by providing this separation space Y, the outer periphery of the first diaphragm 25 that radiates sound waves on the front surface side, the outer periphery of the second diaphragm 6 that is stronger and has a higher frequency for dividing and vibrating than the first diaphragm 25. A structure in which the side is reinforced is realized.

  In the double diaphragm structure of the speaker 22 of the present embodiment, the frequency fh of the first mode in which the outer peripheral side starts split vibration is about 4.0 kHz, and the first diaphragm 5 and the second vibration are below that frequency. The plate 6 is in piston vibration. In the speaker vibration system of the double diaphragm structure that forms the separation space Y of the speaker 22 of this embodiment, the frequency f1 of the mode in which the outer peripheral side of the first diaphragm 25 starts the divided vibration is higher and the outer peripheral side starts the divided vibration. The second diaphragm 6 having the mode frequency f2 can be pushed up to a higher frequency, and the piston vibration region can be expanded as compared with the conventional case.

  Further, in the surface material 25e provided in the first diaphragm 25 of this embodiment, the woven fabric having anisotropy forming the surface material 25e is a twill weave of polyethylene naphthalate fiber, and the warp and weft of the woven fabric Since the size of the composition ratio is about 1.2 or more, the change in Young's modulus depending on the direction of the history becomes large. The first diaphragm 25 provided with the surface material 25e disperses the resonance frequency in the high range, and the sound pressure frequency characteristic is likely to be flat, and the high range is not strict in terms of audibility.

  The first adhesive Ad1 applied to the engaging recess 25d of the first diaphragm 25 and the engaging portion 6b of the second diaphragm 6 engaged therewith is the same rubber-based adhesive as in the previous embodiment. It is an adhesive that has a relatively large Young's modulus after the adhesive is cured, is hard, and has low internal loss. Further, the second adhesive Ad2 different from the first adhesive Ad1 that is applied and filled in the separation space Y defined between the first diaphragm 25 and the second diaphragm 6 is the same as in the previous embodiment. In the case of the same acrylic resin emulsion adhesive, the adhesive may have a relatively small Young's modulus after the adhesive is cured and is soft and has a large internal loss. For example, when the first adhesive Ad1 is not a rubber-based adhesive but an epoxy-based adhesive that is relatively harder and harder than the rubber-based adhesive, or an acrylic adhesive, the second adhesive Ad2 is used. A rubber adhesive may be used. The first adhesive Ad1 and the second adhesive Ad2 are preferably applied separately so as not to mix.

  FIG. 8 is an enlarged view of a main part for explaining the speaker vibration system of the speaker 23 (not shown) according to another preferred embodiment, and the X portion shown in FIG. 1 as in the case of FIG. 2 of the previous example. It is sectional drawing to which the part corresponded to was expanded. The speaker 23 is a common speaker as compared with the speaker 1 of the previous embodiment, except that the configuration of the first diaphragm 5 constituting the double diaphragm structure is different from that of the previous embodiment. Therefore, the description of the configuration of the common voice coil bobbin 2, the second diaphragm 6, and the edge 7 is omitted.

  The first diaphragm 25 of the present embodiment is similar to the first diaphragm 25 of the third embodiment described above, and is a base (a diaphragm portion 25a, an engagement member) made of a paper material formed by making paper fibers. Including a flange portion 25b, a ridge line portion 25c, and an engagement recess 25d. This is a vibration plate exposed to the front surface side, and in the case of the third embodiment, the surface material 25e adhered to the front surface side of the substrate. It is a diaphragm which is different in that it is not provided. Specifically, as described above, the base of the first diaphragm 25 is a paper cone formed by papermaking, press drying, cutting and molding. The inner diameter end of the first diaphragm 25 is connected to the outer curved surface of the voice coil bobbin 2 with an acrylic adhesive.

Even if the first diaphragm 25 of the present embodiment is a paper cone having a paper material as a base material, the first diaphragm 25 has the following physical properties, and the frequency f1 of the mode in which the outer peripheral side of the single first diaphragm 25 divides and vibrates is , About 2.5 kHz. Since the first diaphragm 25 of the present embodiment does not include the surface material 25e, the first diaphragm 25 does not exhibit remarkable anisotropy such that the Young's modulus varies greatly with the circumstances. However, since the first diaphragm 25 of the present embodiment can be reduced in weight by the amount not provided with the surface material 25e, the reproduction efficiency of the speaker 21 can be increased.
(Example 4): 1st diaphragm 25
Thickness t1 0.35mm
Weight 2.5g
Weight per unit area 281 g / m ²
Young's modulus E 2.6E + 9Pa
Internal loss tan δ1 0.13
Density (specific gravity) ρ1 0.80 g / cm ³

  The second diaphragm 6 of this embodiment is the same as that of the previous embodiment. As a result, the Young's modulus E2 of the second diaphragm 6 is smaller than the Young's modulus E1 of the first diaphragm 25. The internal loss δ2 of the second diaphragm 6 is larger than the internal loss δ1 of the first diaphragm 25, and the specific gravity ρ2 of the second diaphragm 6 is smaller than the specific gravity ρ1 of the first diaphragm 25. Satisfy the established relationship.

  Further, the speaker vibration system of the double diaphragm structure of the speaker 23 of the present embodiment is the second diaphragm 6 defined as a portion to which the inner peripheral portion 7b of the edge 7 is connected, as in the previous embodiment. The outer peripheral edge portion of the first diaphragm 25 and the first diaphragm 25 form a separation space Y in which the distance away from the engagement portion 6b of the second diaphragm 6 increases toward the inner periphery. Therefore, by providing this separation space Y, the outer periphery of the first diaphragm 25 that radiates sound waves on the front surface side, the outer periphery of the second diaphragm 6 that is stronger and has a higher frequency for dividing and vibrating than the first diaphragm 25. A structure in which the side is reinforced is realized.

  In the double diaphragm structure of the speaker 23 of the present embodiment, the frequency fh of the first mode in which the outer peripheral side starts split vibration is about 3.5 kHz, and the first diaphragm 25 and the second vibration are below that frequency. The plate 6 is in piston vibration. In the speaker vibration system having a double diaphragm structure that forms the separation space Y of the speaker 1 of the present embodiment, the frequency f1 of the mode in which the outer peripheral side of the first diaphragm 25 starts divided vibration is higher and the outer peripheral side starts higher divided vibration. The second diaphragm 6 having the lowest mode frequency f2 is pushed up to a higher frequency, and the piston vibration region can be expanded as compared with the conventional case.

  FIG. 9 is a schematic cross-sectional view of a speaker 31 according to another preferred embodiment of the present invention. The speaker 31 does not include the bullet-shaped equalizer 9 as compared with the speaker 1 of the previous embodiment, and the configuration of the first diaphragm constituting the double diaphragm structure is different from that of the previous embodiment. Are almost common speakers. Specifically, the speaker 31 includes a first diaphragm 35 in which an inverted dome-shaped central portion 33 is formed integrally with a diaphragm portion 35a, and is different in that the bullet-shaped equalizer 9 is not provided. This is common in that the second diaphragm 6 is shared with the example. Therefore, description of common configurations is omitted.

  As with the first diaphragm 25 of the previous embodiment, the first diaphragm 35 constituting the speaker 31 is a base (a diaphragm portion, an engagement plate) made of a paper material formed by making paper fibers. Part, ridge line part, and engagement concave part) is a diaphragm exposed to the front side, and is a diaphragm not provided with the surface material 25e bonded to the front side of the base. Specifically, the base of the first diaphragm 35 is a paper cone formed by paper making, press drying, cutting the outer peripheral side leaving the central portion 33. Further, the first diaphragm 35 has a connecting portion 32 connected to the end of the voice coil bobbin 2 on the inner peripheral side of the substantially cone-shaped base, and an inverted dome-shaped central portion 33 covering the inner peripheral side of the connecting portion 32. Are formed integrally with the base body. The connection part 32 is prescribed | regulated from the level | step difference shape | molded by cyclic | annular form, or the rib from which thickness changes in part. The end portion of the voice coil bobbin 2 is connected to the connecting portion 32 of the first diaphragm 35 with an acrylic adhesive.

Even if the first diaphragm 35 of the present embodiment is a paper cone having a paper material as a base material, the first diaphragm 35 has the following physical properties, and is the lowest mode in which the outer peripheral side of the single first diaphragm 35 divides and vibrates. The frequency f1 is set to about 2.8 kHz. Since the first diaphragm 35 of the present embodiment does not include a surface material, the first diaphragm 35 does not exhibit a remarkable anisotropy such that the Young's modulus varies greatly with the circumstances. However, since the first diaphragm 35 of the present embodiment can be reduced in weight by the amount not including the surface material, the reproduction efficiency of the speaker 31 can be increased.
(Example 5): First diaphragm 35
Thickness t1 0.35mm
Weight 2.5g
Weight per unit area 281 g / m ²
Young's modulus E1 2.6E + 9Pa
Internal loss tan δ1 0.13
Density (specific gravity) ρ1 0.8 g / cm ³

  Further, in the speaker vibration system of the double diaphragm structure of the speaker 31 of the present embodiment, the second diaphragm 6 defined as a portion to which the inner peripheral portion 7b of the edge 7 is connected, as in the previous embodiment. The outer peripheral edge portion of the first diaphragm 35 and the first diaphragm 35 form a separation space Y in which the distance away from the engagement portion 6b of the second diaphragm 6 increases toward the inner periphery. Therefore, by providing this separation space Y, the outer periphery of the first diaphragm 35 that radiates sound waves on the front surface side, the outer periphery of the second diaphragm 6 that is stronger and has a higher frequency of splitting vibration than the first diaphragm 35. A structure in which the side is reinforced is realized.

  Since the rigidity of the first diaphragm 35 of the present embodiment is enhanced by providing the central portion 33, a stronger double diaphragm structure is realized, and the frequency of the mode in which the outer peripheral side starts split vibration is higher. To increase the piston vibration area. In addition, since the first diaphragm 35 includes a connecting portion 32 that is connected to the end of the voice coil bobbin 2, the voice coil bobbin 2 is in close contact with and connected to the first diaphragm 35, thereby having a highly rigid double diaphragm structure. The vibration system of the speaker is configured. Therefore, it is possible to realize the speaker 31 having excellent reproduction sound quality with less peak dip on the sound pressure frequency characteristic.

  FIG. 10 is a schematic cross-sectional view of a speaker 41 according to another preferred embodiment of the present invention. The speaker 41 is substantially the same as the speaker 31 of the previous embodiment except that the configuration of the first diaphragm 45 constituting the double diaphragm structure is different from that of the previous embodiment. . Specifically, the speaker 41 is different in that it includes a first diaphragm 45 in which a dome-shaped central portion 43 is formed integrally with a diaphragm portion, and includes a second diaphragm 6 that is common to the previous embodiment. Common points. Therefore, description of common configurations is omitted.

  The first diaphragm 45 constituting the speaker 41 is thermoset on a base material that is a laminate including a woven fabric layer or a nonwoven fabric layer made of inorganic fibers or natural fibers, like the first diaphragm 5 of the previous embodiment. And a surface material 44 bonded to the front surface side of the substrate, and the surface material 44 is a diaphragm exposed on the front surface side. Specifically, the substrate is obtained by laminating a nonwoven fabric of technola fibers and a nonwoven fabric of cotton, impregnating with an unsaturated polyester resin and hot press molding, and the surface material 44 is formed on the substrate with a thermoplastic adhesive. The woven fabric of silk woven silk fibers is placed along with the hot melt film on the one that has been coated and dried, and these are integrated by hot press molding. The woven fabric of cocoon silk fibers forming the surface material 44 has a raw silk ratio of warp 21 / 2d of 130 yarns / cm and a weft yarn of 21 / 3d 49 yarns / cm. It was made into 3 piece 5 piece lion weave.

The first diaphragm 45 of the present embodiment has the following physical properties, and the frequency f1 of the mode in which the outer peripheral side of the single first diaphragm 45 vibrates separately is set to about 3.5 Hz. Since the first diaphragm 45 of the present embodiment includes the surface material 44 made of cocoon-woven silk fibers, the Young's modulus exhibits anisotropy that greatly changes over time. The first diaphragm 45 provided with the surface material 44 disperses the resonance frequency in the high range, and the sound pressure frequency characteristic is likely to be flat, and the high frequency is not strict in terms of hearing.
(Example 6): 1st diaphragm 45
Thickness t1 0.3mm
Weight 3.9g
Weight per unit area 439 g / m ²
Young's modulus E11 (longitudinal direction) 3.5E + 9Pa
Young's modulus E12 (weft direction) 3.1E + 9Pa
Internal loss tan δ1 0.1
Density (specific gravity) ρ1 1.2 g / cm ³

  Therefore, the speaker vibration system of the double diaphragm structure of the speaker 41 of the present embodiment is the second diaphragm 6 that is defined as a portion to which the inner peripheral portion 7b of the edge 7 is connected, as in the previous embodiment. The outer peripheral edge part of the first diaphragm 45 forms a separation space Y in which the separation distance increases from the engagement part 6b of the second diaphragm 6 toward the inner peripheral side. Therefore, by providing the separation space Y, the outer periphery of the first diaphragm 45 that radiates sound waves on the front surface side has a higher outer periphery of the second diaphragm 6 that has a higher frequency of split vibration than the first diaphragm 45. A structure in which the side is reinforced is realized.

  In addition, the first diaphragm 45 includes a connecting portion 42 connected to the end portion of the voice coil bobbin 2 on the inner peripheral side of the substantially cone-shaped base, and a dome-shaped central portion 43 covering the inner peripheral side of the connecting portion 42. Are formed integrally with the base body. The connecting portion 42 is defined by a plurality of conical projections that are annularly spaced apart. The conical protrusion is a substantially conical protrusion formed by curing the thermosetting resin so as to protrude from the back side of the diaphragm portion 45 a of the first diaphragm 45. That is, the conical protrusion does not include a base material, and is preferably formed of unsaturated polyester. Since the curing speed is fast and the curing temperature is low, the production is easy, and the connecting portion 42 having excellent internal loss can be obtained. Since the connecting portion 42 is impregnated with the thermosetting resin on the base material of the vibration plate portion 45a, the thermosetting resin is dropped on the shape portion of the connecting portion 42 of the mold and cured, so that the connecting portion 42 is extremely manufactured. Simplified.

  Since the first diaphragm 45 of the present embodiment is provided with the central portion 43 and the rigidity of the first diaphragm is increased, a stronger double diaphragm structure is realized, and the frequency of the mode in which the outer peripheral side starts split vibration. Can be pushed up to a higher frequency to expand the piston vibration region. In addition, since the first diaphragm 45 includes a connecting portion 42 that is connected to the end portion of the voice coil bobbin 2, a highly rigid double diaphragm so that the voice coil bobbin 2 is closely connected to the first diaphragm 45. The vibration system of the structured speaker is constructed. Therefore, it is possible to realize the speaker 41 having excellent reproduction sound quality with less peak dip on the sound pressure frequency characteristic.

  In addition, although preferable embodiment of this invention was described, this invention is not limited to these embodiment. In the speaker of the present invention including the first diaphragm formed by impregnating the base material with the thermosetting resin, for example, the connecting portion 42 of the first diaphragm 45 is formed by curing the thermosetting resin. The plurality of conical protrusions projecting to the back side of the voice coil bobbin 2 and connecting to one end of the voice coil bobbin 2. If so, the size and arrangement of the conical protrusions are not limited.

  The vibration system of the speaker of the present invention can be suitably applied to a speaker used for various applications (for home use and in-vehicle use). Furthermore, the present invention can be applied to an arbitrary speaker such as a woofer that reproduces a low frequency region or a full range speaker that also reproduces a high frequency region. The vibration system of the present invention can be applied not only to a speaker but also to a microphone.

1, 2, 22, 23, 31, 41, 100 Speaker 2 Voice coil bobbin 3 Voice coil 4 Damper 5, 25, 35, 45, 50 First diaphragm 5a, 25a Diaphragm portion 5b, 25b Engagement flange 5c, 25c Ridge part 5d, 25d Engaging recess 5e, 25e, 44 Surface material 6, 60 Second diaphragm 6a, 60a Diaphragm part 6b, 60b Engaging part 7, 70 Edge 7a, 70a Outer part 7b, 70b Inner part 7c, 70c Support movable part 7d, 70d Annular recess 8 Frame 9 Equalizer 10 Magnetic circuit

Claims (3)

A substantially corn-shaped first diaphragm disposed on the front side that emits sound waves;
A substantially cone-shaped second diaphragm disposed on the back side of the first diaphragm and connected to the outer circumference side of the first diaphragm on the outer circumference side thereof;
A voice coil including a substantially cylindrical bobbin to which the inner peripheral sides of the first diaphragm and the second diaphragm are connected to be separated from each other;
An outer peripheral part connected to the frame, an inner peripheral part connected to the outer peripheral side of the first diaphragm or the second diaphragm, a support movable part defined between the outer peripheral part and the inner peripheral part, An edge having
The first diaphragm is extended so as to be folded back from the outer peripheral end portion thereof, and an engagement flange portion that defines a convex ridge line portion on the front surface side and defines an engagement concave portion on the back surface side of the ridge line portion. Have
Second diaphragm, have a engagement portion engaged with the engaging recess of the first diaphragm at its outer peripheral end portion,
The edge has an annular recess with which the engagement flange of the first diaphragm is engaged;
The outer peripheral edge of the second diaphragm, which is defined as the portion where the inner peripheral part of the edge is connected, is located on the inner peripheral side from the engaging part of the second diaphragm between the second diaphragm and the first diaphragm. Forming a separation space that increases the separation distance toward
A first adhesive applied to the engaging recess or the engaging portion, the engaging recess of the first diaphragm and the engaging portion of the second diaphragm engaging with the engaging recess. Concatenated with
A second adhesive different from the first adhesive is applied and filled in the separation space defined between the first diaphragm and the second diaphragm;
speaker. The first diaphragm includes a connecting portion connected to an end portion of the bobbin, and a central portion covering the inner peripheral side of the connecting portion integrally with the base on the inner peripheral side of the substantially cone-shaped base. Molded and equipped,
The speaker according to claim 1 . A damper whose inner peripheral end is connected to the bobbin of the voice coil;
A frame to which the outer peripheral portion of the edge and the outer peripheral end of the damper are coupled;
A magnetic circuit having a magnetic air gap to which the frame is coupled and the coil of the voice coil is disposed;
The speaker according to claim 1 or 2 .

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