JP2012070148A - Speaker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a speaker that implements favorable reproduction sound quality with minor peaks/dips on a sound pressure-frequency characteristic by increasing the rigidity of a speaker vibration system of a dual diaphragm structure in which a diaphragm and a bobbin of a voice coil are coupled, even when the other front side diaphragm constituting the vibration system has a surface material containing a woven fabric.SOLUTION: The speaker includes the first, substantially coned diaphragm arranged on the front side, the second, substantially coned diaphragm arranged behind the first diaphragm and coupled at an outer circumference to an outer circumference of the first diaphragm, and the voice coil including the substantially cylindrical bobbin coupled with inner circumferences of the first diaphragm and second diaphragm separately. The second diaphragm has a base including the inner circumferential portion coupled to the bobbin, and a plurality of engaging portions extended radially outward from the inner circumferential portion of the base so as to engage an outer circumferential end in an engaging concave of the first diaphragm, and adjacent engaging portions of the second diaphragm engage in the engaging concave of the first diaphragm separately.

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). Also, a sub-cone vibrating body is fastened to the outer periphery of the voice coil bobbin that stands upright at the center bottom of the speaker frame, and at least the tip widened portion of the sub-cone vibrating body is fastened to the flat plate-like vibrating plate. In the flat plate type speaker device that is elastically held by the speaker frame, the sub-cone vibrator is constituted by two or more pieces, and a tip widening portion of each piece of the sub-cone vibrator is provided as a vibration of the flat plate-like diaphragm. There is a flat speaker device characterized in that it is fixed to a part of the nodal portion (Patent Document 4).

  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 5). 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 6). 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) JP 59-171399 A (FIGS. 4 to 8) 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. In particular, when the first diaphragm on the front side has a surface material including a woven fabric, the material anisotropy of the woven fabric is strong in the direction of warp and weft and weak in the angle direction of 45 degrees therebetween. Therefore, there is a problem that the influence of the divided vibration mode of the first diaphragm is increased.

  The present invention has been made in order to solve the above-described problems of the prior art, and the object thereof is a case where the first diaphragm on the front surface side constituting the vibration system has a surface material including a woven fabric. However, the speaker diaphragm system with a double diaphragm structure that connects the first diaphragm, the second diaphragm, and the bobbin of the voice coil has high rigidity, and the reproduced sound quality has little peak dip in the sound pressure frequency characteristics. It is to provide an excellent speaker.

  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 that is connected with the inner peripheral sides of the first diaphragm and the second diaphragm being separated from each other, and the first diaphragm is An engagement collar that extends from the outer peripheral end of the substantially cone-shaped base, defines a convex ridgeline on the front side, and defines an engagement recess on the backside of the ridgeline, and the base And a surface material including a woven fabric composed of any one of a plain weave, a twill (oblique) weave, and a satin (weaver) weave including warps and wefts, and the second diaphragm is a bobbin A base including an inner peripheral portion connected to the base, and an outer peripheral end portion extending radially outward from the inner peripheral portion of the base A plurality of engaging portions that engage with the engaging recesses of the first diaphragm, and the engaging portions of the adjacent second diaphragms are spaced apart from each other and engage with the engaging recesses of the first diaphragm, respectively. To do.

  Preferably, in the speaker of the present invention, the engaging portion of the second diaphragm is formed in four directions in rotational symmetry with respect to the center point of the base, and the engaging portion and the center point of each second diaphragm are arranged. The first diaphragm and the second diaphragm are arranged so that the connecting straight line is deviated by about 45 degrees from the direction of the warp of the woven fabric constituting the surface material of the first diaphragm or the direction of the weft. .

  Preferably, in the speaker of the present invention, the first diaphragm has a base 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 The substrate has a substrate based on a paper material formed by forming a fiber and the second diaphragm has a substrate based on a paper material formed by forming a paper fiber.

  Preferably, in the speaker of the present invention, the first diaphragm is connected to the inner peripheral side of the substantially cone-shaped base on the inner peripheral side of the connecting part, and a central part that covers the inner peripheral side of the connecting part. Are molded integrally with the base.

  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 extends so as to be folded back from the outer peripheral end portion thereof, defines an 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; and And a surface material including a woven fabric made of any one of a plain weave, a twill (oblique) weave and a satin (weaver) weave which is bonded to the front surface side of the substrate. 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. The second diaphragm extends from the inner periphery of the base to the outer side in the radial direction and is engaged with the engaging recess of the first diaphragm at the outer peripheral end. And the first diaphragm and the second diaphragm are connected by a first adhesive applied thereto. 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.

  Specifically, the first diaphragm is a speaker diaphragm in which a substrate 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, A surface material including a woven fabric of silk fiber or polyethylene naphthalate fiber made of either twill (oblique) weave or satin (weaver) weave 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 plurality of engaging portions of the outer peripheral edge portion of the second diaphragm defined as the portion where the inner peripheral portion of the edge is connected are between the first diaphragm and the first diaphragm. In addition, a separation space is formed in which the separation distance increases from the engagement portion of the second diaphragm 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.

  Here, since the second diaphragm has a plurality of engaging portions that extend radially outward from the inner peripheral portion of the base body and engage with the engaging concave portions of the first diaphragm at the outer peripheral end portion thereof, The engaging portions of the matching second diaphragm are separated from each other and engaged with the engaging recesses of the first diaphragm. That is, since the second diaphragm is cut away so that adjacent engaging portions are separated from each other, the space between the engaging portions is eliminated, so that the weight of the second diaphragm is reduced. The diaphragm area of the second diaphragm can be reduced, and the radiated sound from the second diaphragm can be reduced. Moreover, arbitrary anisotropy can be given to the rigidity of a 2nd diaphragm by providing a some engaging part in the outer peripheral edge part of a 2nd diaphragm. Preferably, in the case where the engaging portions of the second diaphragm are formed in four directions in rotational symmetry with respect to the center point of the base body, the angle between the engaging portions of the second diaphragm is 45 degrees. There are four gaps in the angular direction.

  In the speaker of the present invention, the straight line connecting the respective engagement portions and the center point of the second diaphragm is approximately the direction of the warp of the woven fabric constituting the surface material of the first diaphragm or the direction of the weft. The first diaphragm and the second diaphragm need only be arranged so as to be shifted by 45 degrees. When the first diaphragm on the front side has a surface material including a woven fabric, the material anisotropy of the woven fabric is strong in the direction of warp and weft and weak in the angle direction of 45 degrees between them. Even when the influence of the divided vibration mode of the first diaphragm is increased, the first diaphragm and the second diaphragm are matched so that the direction in which the rigidity of the first diaphragm is weak and the direction in which the second diaphragm is strong. By disposing the two diaphragms, it is possible to realize a speaker excellent in reproduction sound quality, in which divided vibrations are suppressed from each other and there are few peaks and dips in 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 top view explaining the 1st diaphragm 5 of the speaker 1 of this invention. Example 1 It is a perspective view explaining the speaker vibration system of the speaker 1 of the Example of this invention. Example 1 It is a figure explaining the vibration mode 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)

  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. FIG. 3 is a plan view for explaining the first diaphragm 5 constituting the speaker vibration system of the speaker 1, and FIG. 4 is a perspective view for explaining the speaker vibration system of the speaker 1. As will be described later, a part of the structure and the internal structure of the speaker 1 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 the surface material, along with a plain woven PEN fiber woven fabric, and heat-pressing them to integrate them. As shown in the plan view of FIG. 3 where the surface material 5e of the first diaphragm 5 is exposed, the plain woven PEN fiber woven fabric forming the surface material 5e has warps and wefts. Therefore, since the woven fabric of plain weave PEN fibers has a weaving direction in which the PEN fibers intersect at almost right angles to the machine direction and the transverse direction, the direction along this weave direction (direction of warp and weft: FIG. 3) There is a difference in strength between the dx1 direction and the dx2 direction) and a direction not along the weaving direction (angle direction of 45 degrees between warp and weft: dy1 direction and dy2 direction in FIG. 3). As a result, the first diaphragm 5 in which the surface material 5e including the woven fabric of plain weave PEN fibers is integrated is strong in the direction of the warp and the weft, and in an angle direction of 45 degrees oblique between the directions of the warp and the weft. Will exhibit the material anisotropy of the woven fabric, which is weak.

  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. Is a substantially cone-shaped diaphragm defined by different R curves and straight lines. The second diaphragm 6 has a paper base formed by paper making. The substantially cone-shaped diaphragm portion 6a has an inner diameter of about 39.5 mm and an outer diameter of about 111. It is 5 mm and the height is about 31.2 mm. Further, as shown in FIG. 4, the second diaphragm 6 is a diaphragm having a base body cut out in four radial directions as viewed from the center. The outer peripheral portion 6c extends radially outward. The inner peripheral portion 6 c 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 has four engagement portions 6b that engage with the engagement recesses 5d of the first diaphragm 5 at the outer peripheral ends of the four diaphragm portions 6a.

  As a result, since the second diaphragm 6 is cut away so that the adjacent engaging portions 6b are separated from each other, the through holes 6d are defined in four directions between the engaging portions 6b. Each of the four diaphragm portions 6a and the engaging portions 6b of the second diaphragm 6 is formed in four directions rotationally symmetrically with respect to the center point, and is arranged at 90 ° intervals in the circumferential direction. Each has a width of about 30 °. Therefore, between the engaging portions 6b separated by the through hole 6d, the angle in the circumferential direction corresponds to about 60 °, and the second diaphragm 6 is reduced in weight by defining the through hole 6d. Yes. Further, since the second diaphragm 6 is cut away so that the adjacent engaging portions 6b are separated from each other on the outer peripheral end side, the directions of the four diaphragm portions 6a and the engaging portions 6b ((( It has an anisotropy that it is strong in the dz1 direction (corresponding to the dy1 direction) and (dz2 direction) (corresponding to the dy2 direction) and weak in the direction of the four through holes 6d.

  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 four engaging portions 6b that engage with the engaging recesses 5d of the first diaphragm 5 at the outer peripheral end thereof. Since the inner peripheral portion 7 b of the edge 7 is bonded and fixed, the engagement flange portion 5 b of the first diaphragm 5 engages with the annular recess 7 d of the support movable portion 7 c 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 second diaphragm 6 has four engagement portions 6b that engage with the engagement recesses 5d of the first diaphragm 5 at the outer peripheral end thereof, when the first adhesive Ad1 is applied thereto, The plate 5 and the second diaphragm 6 are connected. 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.

  By the way, as shown in FIG. 4, in the speaker vibration system of the double diaphragm structure of the speaker 1 of this embodiment, the surface material 5e including a plain woven PEN fiber woven fabric is used to have anisotropy. 1 diaphragm 5 and a notched second diaphragm 6 having anisotropy that is strong in the direction of the four diaphragm portions 6a and the engaging portion 6b and weak in the direction of the four through holes 6d. Are arranged so as to reinforce each other. That is, the four diaphragm portions 6a and the engaging portions 6b of the second diaphragm 6 are formed in four directions (dz1 direction and dz2 direction in FIG. 4) in rotational symmetry with respect to the center point of the base body. The straight line connecting the engaging portion 6b of each second diaphragm 6 and the center point is the direction of the warp or weft of the woven fabric constituting the surface material 5e of the first diaphragm 5 (direction dx1, direction dx2 in FIG. 3). The first diaphragm 5 and the second diaphragm 6 are arranged so as to be shifted by about 45 degrees. In other words, the straight line connecting the engaging portion 6b of each second diaphragm 6 and the center point is inclined at 45 degrees between the warp and weft directions of the woven fabric constituting the surface material 5e of the first diaphragm 5. The first diaphragm 5 and the second diaphragm 6 are arranged so as to coincide with the angular direction (the dy1 direction and the dy2 direction in FIG. 3).

  That is, in the speaker vibration system of the double diaphragm structure of the speaker 1, a direction that does not follow the weaving direction which is a weak direction of the first diaphragm 5 having anisotropy (an angle direction of 45 degrees oblique between the warp and the weft) : Dy1 direction and dy2 direction in FIG. 3) and the first vibration so that the directions of the four diaphragm portions 6a and the engaging portions 6b, which are strong directions of the second diaphragm 6 having anisotropy, coincide with each other. A plate 5 and a second diaphragm 6 are disposed. This is a relationship in which the first diaphragm 5 and the second diaphragm 6 are arranged so that the direction in which the first diaphragm 5 is weak and the direction in which the second diaphragm 6 is strong match. . Therefore, the influence of the divided vibration mode of the first diaphragm 5 is influenced by the material anisotropy of the woven fabric constituting the surface material 5e which is strong in the warp and weft directions and weak in the angle direction of 45 degrees therebetween. Even if it becomes large, the divided vibration is mutually suppressed by the second diaphragm 6 having anisotropy, and the speaker 1 having excellent reproduction sound quality with less peak dip on the sound pressure frequency characteristic is realized. Can do.

  FIG. 5 is a diagram for explaining vibration modes of the speaker 1 of the present invention and the speaker 100 (not shown) of the comparative example. The speaker 100 of the comparative example is an electrodynamic type speaker having a speaker vibration system that does not have a double diaphragm structure that does not have the second diaphragm 6 as compared with the speaker 1 of the present embodiment. The speaker vibration system of the speaker 100 of the comparative example is different only in that the second diaphragm 6 is not provided. Therefore, description of the common voice coil bobbin 2, voice coil 3, damper 4, first diaphragm 5, edge 7, frame 8, equalizer 9, and magnetic circuit 10 is omitted.

  As shown in FIG. 5A, in the speaker 1 of this embodiment, 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, Since the second diaphragm 6 is arranged so as to reinforce the anisotropy of the surface material 5e of the diaphragm 5, a substantially concentric vibration mode distribution as in the case where the surface material 5e is isotropic is provided. Is seen. On the other hand, as shown in FIG. 5B, in the speaker 100 of the comparative example, the second diaphragm 6 that reinforces the first diaphragm 5 is not disposed, so that the surface material 5e of the first diaphragm 5 is different. The directivity appears remarkably, and the vibration mode distribution with four rotational symmetry appears from a low frequency. Therefore, in the speaker 100 of the comparative example, the piston vibration region of the speaker vibration system becomes narrow, and the operation of the speaker vibration system becomes unstable.

  FIG. 6 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 mode, which is the first mode in which the outer peripheral side starts split vibration, is about 2.9 kHz, and the first vibration is obtained at a frequency lower than that. 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 is a mode in which split vibration is started due to the anisotropy of the surface material 5e of the first diaphragm 5 of the first diaphragm 5. The frequency is pushed up to a higher frequency (about 2.9 kHz in the present embodiment) by the second diaphragm 6 which is arranged so as to be mutually reinforcing and in a mutually reinforcing relationship, The piston vibration area can be expanded. 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 1.8 kHz, and the region where the first diaphragm 5 undergoes piston vibration becomes narrow. ing.

  In a general speaker vibration system having a double diaphragm structure, the total weight of the speaker vibration system becomes heavy due to the arrangement of the second diaphragm 6 behind the first diaphragm 5, resulting in a speaker with low efficiency. There is a problem to say. However, the speaker 1 of the present embodiment has an advantage that the second diaphragm 6 can be reduced in weight because the second diaphragm 6 is notched and the space between the adjacent engaging portions 6b is eliminated. Moreover, since the 2nd diaphragm 6 is comprised so that the through-hole 6d may be prescribed | regulated, the diaphragm area of the 2nd diaphragm 6 substantially reduces. As a result, the double diaphragm structure of the speaker 1 of this embodiment has an advantage that unnecessary radiated sound from the second diaphragm 6 can be reduced.

  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.

  Further, the surface material 5e of the first diaphragm 5 of the present embodiment is such that the anisotropy woven fabric forming this has a woven fabric warp / weft component ratio of about 1.2 or more. If the woven fabric is any one of plain weave, twill weave, satin weave, satin weave and satin weave, the Young's modulus varies greatly with the circumstances, and the first diaphragm 5 provided with the surface material 5e has a dispersed high-frequency resonance frequency. As a result, the sound pressure frequency characteristic is likely to be flat, and the high frequency range is eliminated from the viewpoint of hearing. 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. Further, the first diaphragm 5 formed by impregnating a base material with a thermosetting resin may be formed integrally with a portion corresponding to a dust cap.

  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.

DESCRIPTION OF SYMBOLS 1,100 Speaker 2 Voice coil bobbin 3 Voice coil 4 Damper 5 1st diaphragm 5a Diaphragm part 5b Engagement part 5c Ridge part 5d Engagement recessed part 5e Surface material 6 2nd diaphragm 6a Diaphragm part 6b Engagement part 6c Inner peripheral part 6d Through hole 7 Edge 7a Outer peripheral part 7b Inner peripheral part 7c Supporting movable part 7d Annular recess 8 Frame 9 Equalizer 10 Magnetic circuit

Claims (5)

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 that is connected with the inner peripheral sides of the first diaphragm and the second diaphragm spaced apart from each other;
The first diaphragm extends so as to be folded back from the outer peripheral end of the substantially cone-shaped base, defines a convex ridge line on the front side, and defines an engagement recess on the back side of the ridge line. An engagement collar, and a surface material including a woven fabric made of any one of a plain weave, a twill (oblique) weave, and a satin (weaver) weave bonded to the front side of the base body. ,
A base including an inner periphery connected to the bobbin, and a second diaphragm extending radially outward from the inner periphery of the base and engaging the first diaphragm at an outer peripheral end thereof A plurality of engaging portions that engage with the recesses, and the engaging portions of the adjacent second diaphragms are spaced apart from each other and engage with the engaging recesses of the first diaphragm, respectively.
speaker. The engaging portion of the second diaphragm is formed in four directions in rotational symmetry with respect to the center point of the base,
A straight line connecting the engaging portion and the center point of each second diaphragm is the direction of the warp of the woven fabric constituting the surface material of the first diaphragm, or the direction of the weft The first diaphragm and the second diaphragm are arranged so as to be shifted by about 45 degrees.
The speaker according to claim 1. The first diaphragm is formed by making a base material including a woven fabric or a nonwoven fabric made of fibers impregnated with a thermosetting resin containing an unsaturated polyester resin, or by making paper fibers. Having a substrate based on paper,
The second diaphragm has the base body based on a paper material formed by making paper fiber.
The speaker according to claim 1 or 2. 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 any one of claims 1 to 3. 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 any one of claims 1 to 4.