JP2007124366A - Magnetic circuit structure of exciter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a magnetic circuit structure of an exciter where high magnetic flux density is secured and thickness can be reduced. <P>SOLUTION: In the magnetic circuit structure of the exciter, a driving side where a magnetic field space is formed by a magnet and a plate inside a bottomed-cylindrical yoke and a coupler provided so that a voice coil wound on a voice coil bobbin may be positioned in the magnetic field space are held elastically by a damper. In the exciter, an edge periphery part of a hole at the plate and that of the screw seat surface projecting part of the coupler are chamfered so as to vibrate overlapped in the case of driving. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a magnetic circuit structure of an exciter of an interior direct drive speaker, and more particularly to a magnetic circuit structure that can secure a high magnetic flux density and can be thinned.

  A magnetic circuit structure of a conventional exciter will be described with reference to FIGS. FIG. 6 is a schematic cross-sectional view showing the magnetic circuit structure of an exciter of the prior art. FIG. 7 is a schematic plan view showing the damper of the exciter.

  Reference numeral 14 denotes a magnetic circuit section of an exciter 19 for an internal direct drive speaker. As shown in FIG. 6, a coupler 24, a voice coil bobbin 26 around which a voice coil is wound, a plate 34, a magnet 39, a yoke 42, a spacer 43, and a damper 44. The dust-proof damper 45, the bracket 47 fixed to the vibration member (vibration plate) 46, the screw 50 for fastening the magnetic circuit portion 14 of the exciter 19 to the bracket 47, and the like.

  The coupler 24 is a base part of the exciter 19 and has a substantially disk shape. A circular protrusion 24a is formed at the center, and a protrusion 47a of a bracket 47 described later is fitted in the center. A hole 24b is formed. Further, since the upper surface of the circular protruding portion 24a is a screw seat surface, a mounting hole through which a screw 50 for fastening to the bracket 47 is inserted is formed in the center portion. An engagement portion 24c for fixing the inner periphery of the voice coil bobbin 26 is formed on the outer side of the circular protrusion 24a, and a mounting portion 24d for a dustproof damper 45 is formed on the outer side of the engagement portion 24c. Yes. Further, on the outer peripheral edge of the coupler 24, a mounting seat portion 24e of the damper 44 protrudes at a position corresponding to the mounting hole 44b of the damper 44, and the back side of the mounting seat portion 24e (with the disc portion of the bracket 47). An annular groove or the like in which the elastic spacer 43 is fitted is formed on this surface. A resin member is used as the material of the coupler 24 and is formed by molding or the like.

  The plate 34 has an annular shape, the outer diameter dimension is determined by the relationship with the inner diameter dimension of the yoke 42 described later, and the hole diameter is formed as a hole through which the circular protrusion 24a of the coupler 24 is inserted.

  The magnet 39 is an annular permanent magnet, and has an outer diameter and an inner diameter that are substantially the same as the outer diameter and the inner diameter of the plate 34.

  The yoke 42 has a cylindrical shape with a bottom, and the inner diameter dimension of the cylinder is a predetermined gap between the outer diameter dimension of the plate 34, that is, the voice coil wound around the voice coil bobbin 26 is engaged with this gap ( The magnetic circuit is formed in a dimension that is loosely inserted). The depth from the opening to the bottom of the cylinder is substantially the same as the thickness of the plate 34 and the magnet 39 plus the hole, and a hole is provided so that the circular protrusion 24a of the coupler 24 is inserted through the center of the bottom. Is formed. In addition, a small-diameter portion (damper fixing portion) for fitting and fixing the inner diameter 44d of the damper 44 is formed on the outer peripheral portion of the opening of the cylinder.

  The bracket 47 is a part for transmitting vibration generated from the magnetic circuit portion 14 of the exciter 19 to the vibration member 46, has a disk shape, and has a protrusion 47a formed at the center. The protruding portion 47a is formed to have a size that fits into the hole 24b of the circular protruding portion 24a of the coupler 24, and a screw hole for fastening the coupler 24 is formed in the central portion of the protruding portion 47a. In addition, the back side of the surface on which the projecting portion 47 a of the disk portion is formed becomes the fixing surface of the vibration member 46. A resin member is used as the material of the bracket 47 and is formed by molding or the like.

  As shown in FIG. 7, the damper 44 is formed with a plurality of arc-shaped elastic support portions 44 a (three locations at an interval of 120 degrees in the present case) independent from predetermined positions on the outer peripheral portion of the annular portion 44 c. A mounting hole 44b is formed at a position corresponding to the mounting seat portion 24e of the coupler 24 at the terminal end of 44a. Further, the inner diameter 44d of the annular portion 44c is formed to fit into a small diameter portion (damper fixing portion) formed on the outer peripheral portion of the opening of the yoke 44. For example, a thin plate spring member made of stainless steel is used as the material of the damper 44.

  Here, the assembly of the magnetic circuit portion of the exciter will be briefly described. First, the plate 34 and the magnet 39 are fixed in a concentric state. Then, the end surface of the fixed magnet 39 is fixed to the bottom surface inside the yoke 42. At this time, the yoke 42 is fixed so as to have a uniform gap between the inner periphery of the yoke 42 and the outer periphery of the plate 34 and the magnet 39, and the damper 44 is attached to a small diameter portion (damper fixing portion) provided on the outer periphery of the opening of the yoke 42. Is inserted and fixed with an adhesive. Next, an elastic spacer 43 is fixed to the annular groove formed in the coupler 24. Then, the voice coil bobbin 26 around which the voice coil is wound is fixed to the engaging portion 24c of the coupler 24 with an adhesive, and the dustproof damper 45 is mounted on the mounting portion 24d of the dustproof damper 45. Next, a damper 44 fixed to the yoke 42 in a state where the coil portion of the voice coil bobbin 26 fixed to the coupler 24 is loosely inserted into a gap formed by the inner periphery of the yoke 42 and the outer periphery of the plate 34. Is fixed to the mounting seat portion 24e of the coupler 24 with a screw, thereby forming a magnetic circuit portion of the exciter.

  Next, the bracket 47 is fixed to a predetermined position of the vibration member 46 (for example, the back side of the ceiling plate of the automobile). Then, by fitting the hole 24b of the circular protrusion 24a of the coupler 24 to the protrusion 47a of the bracket 47 fixed to the vibration member 46 and fastening the coupler 24 to the bracket 47 with the screw 50, the interior direct drive speaker Is configured.

Prior art documents relating to the invention of this application include the following.
JP 2001-293436 A

  In the magnetic circuit structure 14 of the exciter 19 described above, in order to avoid interference between the plate 34 and the screw seat surface of the coupler 24 with respect to the amplitude, the hole diameter is widened to a size that allows the outer shape of the screw seat surface of the coupler 24 to loosely fit on the plate 34. As a result, the amount (volume) of the magnet 39 is reduced, which makes it difficult to secure the necessary magnetic flux density, which may lead to deterioration of acoustic performance. As a countermeasure described above, it is conceivable to make the hole diameter small enough to dodge the head of the screw 50. However, in that case, a height dimension corresponding to the maximum amplitude amount is required, making it difficult to reduce the thickness.

  In addition, although patent document 1 is disclosed as a prior art document regarding the invention of this application, this technique is a multi-function vibration actuator, and the vibrating body which generate | occur | produces a sound is comprised in an actuator. In addition, a sound emission hole for air viscous damping is provided in the cover fixed to the vibration transmission part constructed in the prior art, suppressing unstable operation of the vibrating body near the resonance frequency, and reducing harmonic distortion components. The main purpose is to plan.

  An object of the present invention is to solve the above-described problems, and to provide a magnetic circuit structure of an exciter that can secure a high magnetic flux density and can be thinned.

  The present invention achieves the above-described object, and includes a drive side in which a magnetic field space is formed by a magnet and a plate inside a bottomed cylindrical yoke, and a voice coil wound around a voice coil bobbin. In an exciter magnetic circuit structure in which a coupler provided so as to be located inside is elastically held by a damper, the exciter is close to or overlaps with a portion facing the drive side and the coupler side during driving. Thus, a proximity means capable of vibrating is provided.

  In addition, the proximity means is a screw seat surface protrusion of the coupler provided to fix the exciter with a screw to an annular peripheral portion of the plate hole and a bracket fixed to the vibration member. A chamfering process is performed on the peripheral part of the part.

  Further, the proximity means includes a screw hole protruding portion of a coupler provided to fix the exciter to the vibration member, and the screw hole protruding portion is fitted to the opposing surface of the plate formed in a disc shape. The recessed part to insert is formed, It is characterized by the above-mentioned.

  Further, the plate is formed with a through hole into which the screw hole projecting portion of the coupler is loosely fitted.

  Further, the magnet contact surface of the plate is provided with a recess into which the magnet is fitted, and the magnet is formed to have a volume corresponding to the recess.

  Further, a concave portion into which another magnet is fitted is provided on the back side of the magnet contact surface of the plate, and the plate is provided so as to be sandwiched between two magnets.

  As described above, according to the first aspect of the present invention, a high magnetic flux density can be secured in the magnetic circuit of the exciter of the internal direct drive speaker, and the thickness can be reduced.

  Further, according to claim 2, by chamfering the outer peripheral edge of the screw seat surface of the coupler and the hole of the plate corresponding to the outer peripheral edge, the screw seat surface and the opposing surface of the plate Can be driven (vibrated) by overlapping in the vertical (thickness) direction, so that the dimension in the height direction of the magnetic circuit portion of the exciter can be reduced and miniaturized.

  According to the third aspect of the present invention, since the concave portion into which the screw hole protruding portion is fitted is provided on the opposing surface of the driving side plate facing the screw hole protruding portion of the fixed-side coupler, Since the opposing surface of the plate can overlap and drive (vibrate) in the vertical direction, the height dimension of the magnetic circuit portion of the exciter can be reduced and miniaturized.

  According to the fourth aspect of the present invention, the through-hole in which the screw hole protrusion of the coupler is loosely fitted is provided in the driving side plate, so that it is possible to cope with a larger amplitude and the height direction of the magnetic circuit portion of the exciter. It is possible to reduce the size by reducing the size.

  Further, according to claim 5, by providing the concave portion on the magnet fixing surface side of the drive side plate, the thickness of the magnet can be increased by the amount of the concave portion, the volume of the magnet is increased and the magnetic flux density is increased. Can increase power. Further, the height of the magnetic circuit portion of the exciter can be reduced in size by the amount of the recess compared to the exciter having the same power as the conventional one.

  According to the sixth aspect of the present invention, since the upper and lower surfaces of the plate are sandwiched and fixed by two magnets, the volume of the magnet is increased by the amount of the concave portion provided in the plate, and the magnetic flux density is increased. I can plan up. Further, since the repulsive magnetic circuit is configured, the magnetic circuit is strengthened and the sound quality can be improved.

The present invention improves the performance of a conventional exciter and reduces the size in the height (thickness) direction to reduce the size. A part of the case will be described with reference to FIGS.
(Embodiment 1)
Embodiment 1 of the present invention will be described with reference to FIG. FIG. 1 is a schematic diagram showing a magnetic circuit structure of an exciter according to Embodiment 1 of the present invention, where (a) a plan view and (b) AA cross-sectional view. The present invention is an improvement of a part of the magnetic circuit structure of an exciter according to the prior art. The same components as those of the prior art are denoted by the same reference numerals, description thereof is omitted or simplified, and changes will be mainly described.

  Reference numeral 10 denotes a magnetic circuit portion of the exciter 15 for the interior direct drive speaker. As shown in FIG. 1, the coupler 20, the voice coil bobbin 26 around which the voice coil is wound, the plate 30, the magnet 35, the yoke 41, the spacer 43, and the damper 44. The dustproof damper 45, the bracket 47 fixed to the vibration member (vibration plate) 46, and the screw 50 for fastening the exciter 15 to the bracket 47 are configured.

  The coupler 20 is a base part of the exciter 15 and has a substantially disc shape. A circular protrusion 20a is formed at the center, and a protrusion 47a of a bracket 47 described later is fitted in the center. A hole 20b is formed. Since the upper surface of the circular protruding portion 20a is a screw seat surface, a mounting hole for a screw 50 for fastening to the bracket 47 is formed in the central portion, and a chamfer of about 45 degrees is formed on the outer peripheral end surface of the circular protruding portion 20a. 20c is applied. The dimension of the chamfer 20c is determined by the relationship with the dimension of a chamfer 30a of the plate 30 described later, and the chamfer 20c is made to correspond to the maximum amplitude of the exciter 15 by the dimensions of both the chamfers 20c and 30a. Further, an engaging portion 20d for fixing the inner periphery of the voice coil bobbin 26 is formed on the outer side of the circular protrusion 20a, and a mounting portion 20e for the dustproof damper 45 is formed on the outer side of the engaging portion 20d. Yes. Further, the mounting seat portion 20f of the damper 44 protrudes from the outer peripheral edge portion of the coupler 20 at a position corresponding to the mounting hole 44b of the damper 44, and the rear side of the mounting seat portion 20f (the contact with the disc portion of the bracket 47). An annular groove or the like into which the elastic spacer 43 is fitted is formed on the installation surface. A resin member is used as the material of the coupler 20 and is formed by molding or the like.

  The plate 30 has an annular shape, the outer diameter is determined by the relationship with the inner diameter of the yoke 40, which will be described later, and the hole diameter is formed as a hole through which the head of the screw 50 is inserted. A chamfer 30a of about 45 degrees is provided so as to face (face to face) the chamfer 20c of the coupler 20.

As described above, according to the magnetic circuit unit 10 of the exciter 15 according to the first embodiment of the present invention, the chamfers 20 c and 30 a are applied to the outer peripheral edge of the circular protrusion 20 a of the coupler 20 and the hole of the plate 30. Thus, the circular protrusion 20a of the coupler 20 and the end face of the plate 30 can be driven (vibrated) so as to overlap in the vertical (thickness) direction, so the height (thickness) direction of the magnetic circuit unit 10 of the exciter 15 It is possible to reduce the size by reducing the size. In addition, by chamfering 20c and 30a, the hole diameter through which the head of the screw 50 is inserted can be made smaller than the conventional hole diameter, so the volume of the magnet 35 is increased by that amount, and the magnetic flux density is increased. The power of the exciter 15 can be increased.
(Embodiment 2)
A second embodiment of the present invention will be described with reference to FIGS. FIG. 2 is a schematic sectional view showing the magnetic circuit structure of the exciter according to the second embodiment of the present invention. FIG. 3 is a schematic cross-sectional view showing the magnetic circuit structure of an exciter that is partially different from the second embodiment. In the second embodiment, a part of the first embodiment is changed. The same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted or simplified, and the changed points will be mainly described.

  11 is a magnetic circuit portion of the exciter 16 for the interior direct drive speaker. As shown in FIG. 2, the coupler 21, the voice coil bobbin 26 around which the voice coil is wound, the plate 31, the magnet 36, the yoke 41, the damper 44, and the spacer 43. Further, it is constituted by a dustproof damper 45 and a bracket 48 fixed to the vibration member (vibration plate) 46.

  The coupler 21 is a base part of the exciter 16 and has a substantially disk shape. A screw hole projecting portion 21a is formed in the central portion, and the central portion is screwed into a screw 48a of a bracket 48 described later. A screw hole 21b is formed. Further, an engaging portion 21c for fixing the inner periphery of the voice coil bobbin 26 is formed in the outer direction of the screw hole protruding portion 21a, and a mounting portion 21d for the dustproof damper 45 is formed in the outer direction of the engaging portion 21c. ing. Further, the mounting seat portion 21e of the damper 44 protrudes from the outer peripheral edge portion of the coupler 21 at a position corresponding to the mounting hole 44b of the damper 44, and the rear side of the mounting seat portion 21e (with the disc portion of the bracket 48). An annular groove or the like in which the elastic spacer 43 is fitted is formed on this surface. A resin member is used as the material of the coupler 21 and is formed by molding or the like.

  The plate 31 has a disk shape, and the outer diameter is determined by the relationship with the inner diameter of the yoke 41. On one surface of the disk (on the side facing the screw hole protrusion 21a of the coupler 21). Even in the case of the maximum amplitude, a recess 31a is formed for releasing the contact of the screw hole protrusion 21a of the coupler 21.

  The magnet 36 is a disk-shaped permanent magnet and has an outer diameter dimension substantially the same as the outer diameter dimension of the plate 31.

  The yoke 41 has a bottomed cylindrical shape, and the voice coil wound around the voice coil bobbin 26 is engaged (slowly inserted) in a predetermined gap (magnetic space) between the inner diameter of the cylinder and the outer shape of the plate 31. In addition, the gap should be appropriate so that the magnetic circuit can be configured. Further, the depth from the opening of the cylinder to the bottom is formed to be substantially the same as the thickness of the plate 31 and the magnet 36, and the inner diameter of the damper 44 is inserted into the outer periphery of the opening of the cylinder. A small-diameter portion (stepped portion) for fixing is formed.

  The bracket 48 is a component for transmitting vibration generated from the magnetic circuit portion of the exciter 16 to the vibration member 46, has a disk shape, and a screw for screwing and fastening to the screw hole of the coupler 21 at the center portion. 48a is formed. The length of the screw 48a is set so as not to protrude from the screw hole 21b of the coupler 21 in the fastening state with the coupler 21. Note that the back surface side of the surface on which the screw 48 a is formed is a fixing surface of the vibration member 46. A resin member is used as the material of the bracket 48 and is formed by molding or the like.

  Here, the assembly of the magnetic circuit portion of the exciter will be briefly described. First, the magnet 36 of the plate 31 is fixed in a concentric state. Then, the end face of the fixed magnet 36 is fixed to the bottom surface inside the yoke 41. At this time, the inner periphery of the yoke 41 and the outer periphery of the plate 31 and the magnet 36 are fixed so as to form a uniform gap, and the inner diameter 44d of the damper 44 is fitted into the small diameter portion provided on the outer periphery of the opening of the yoke 41. Secure with the adhesive. Next, an elastic spacer 43 is fixed to the annular groove formed in the coupler 21. Then, the voice coil bobbin 26 around which the voice coil is wound is fixed to the engaging portion 21c of the coupler 21 with an adhesive, and the dustproof damper 45 is attached to the attachment portion 21d. Next, the coil portion of the voice coil bobbin 26 fixed to the coupler 21 is loosely inserted into a gap portion (magnetic space) formed by the inner periphery of the yoke 41 and the outer periphery of the plate 31, and is fixed to the yoke 41. The magnetic circuit portion 11 of the exciter 16 is configured by screwing and fixing the damper 44 to the mounting seat portion 21e of the coupler 21.

  Next, the bracket 48 is fixed to a predetermined position of the vibration member 46 (for example, the back side of the ceiling plate of the automobile). Then, the screw 48a of the bracket 48 fixed to the vibration member 46 is screwed into the screw hole 21b formed in the coupler 21 of the magnetic circuit unit 11 of the exciter 16 and fastened to form an interior direct drive speaker. The

As described above, according to the magnetic circuit unit 11 of the exciter 16 according to the second embodiment of the present invention, the recess 31a (corresponding to the maximum amplitude) for releasing the screw hole protrusion 21a of the coupler 21 on the end surface of the plate 31 is provided. Since the screw hole protrusion 21a fits into the recess 31a during vibration, it can be driven (vibrated) by being overlapped by the recess 31a, so that the magnetic circuit portion 11 of the exciter 16 can be driven. The size in the height (thickness) direction can be reduced to reduce the size. In the description of this example, the recess 31a is provided in the plate 31. In addition, as shown in FIG. 3, the plate 31 is formed in an annular shape, and the inner diameter is formed so as to be loosely fitted into the screw hole protruding portion 21a. By increasing the height of the screw hole protrusion 21a of 21 and increasing the length of the screw 48a of the bracket 48, the fastening strength between the coupler 21 and the bracket 48 can be enhanced, and the amplitude is further increased. Can also respond.
(Embodiment 3)
Embodiment 3 of the present invention will be described with reference to FIG. FIG. 4 is a schematic sectional view showing the magnetic circuit structure of the exciter according to the third embodiment of the present invention.

  Reference numeral 12 denotes an exciter magnetic circuit for an internal direct drive speaker. As shown in FIG. 4, a coupler 22, a voice coil bobbin 26 around which a voice coil is wound, a plate 32, a magnet 37, a yoke 41, a damper 44, a spacer 43, A dust-proof damper 45 and a bracket 49 fixed to the vibration member (vibration plate) 46 are formed.

  The coupler 22 is a base part of the exciter 17 and has a substantially disk shape. The coupler 22 is formed with an engaging portion 22a for fixing the inner periphery of the voice coil bobbin 26. A screw hole 22b to be screwed is formed, and a mounting portion 22e for the dustproof damper 45 is formed on the outer side of the engaging portion 22a. Further, on the outer peripheral edge of the coupler 22, a mounting seat portion 22c of the damper 44 protrudes at a position corresponding to the mounting hole 44b of the damper 44, and the back side of the mounting seat portion 22c (with the disc portion of the bracket 49). An annular groove or the like in which the elastic spacer 43 is fitted is formed on this surface. A resin member is used as the material of the coupler 22 and is formed by molding or the like.

  The plate 32 has a disk shape, and the outer diameter is determined by the relationship with the inner diameter of the yoke 41, and a recess for fixing the magnet 37 on one surface of the disk (on the side where the magnet 37 is fixed). 32a is formed.

  The magnet 37 is a permanent magnet having a stepped cylindrical shape. The outer diameter of the large diameter portion is formed to be substantially the same as the outer diameter of the plate 32, and the outer diameter of the small diameter portion is formed in the recess 32 a of the plate 32. It is formed to a size that fits. The large-diameter portion and the small-diameter portion of the magnet 37 may be formed integrally, or the large-diameter portion and the small-diameter portion may be formed separately and used in an overlapping manner.

  The bracket 49 is a component for transmitting the vibration generated from the magnetic circuit portion 12 of the exciter 17 to the vibration member 46, has a disk shape, and is screwed into the screw hole 22b of the coupler 22 at the center to be fastened. The screw 49a is formed. The length of the screw 49a is set so that it does not protrude from the screw hole 22b of the coupler 22 in a fastening state with the coupler 22. Note that the back side of the surface on which the screw 49 a is formed is a fixing surface of the vibration member 46. A resin member is used as the material of the bracket 49 and is formed by molding or the like.

  Here, the assembly of the magnetic circuit portion of the exciter will be briefly described. First, the small-diameter portion of the magnet 37 is fitted into the concave portion 32a of the plate 32, and the large-diameter portion of the plate 32 and the magnet 37 is fixed in a concentric state. Then, the end surface of the large-diameter portion of the fixed magnet 37 is fixed to the bottom surface inside the yoke 41. At this time, the yoke 41 is fixed so that there is a uniform gap between the inner periphery of the yoke 41 and the outer periphery of the plate 32 and the magnet 37. Then, the inner diameter 44d of the damper 44 is fitted into a small diameter portion provided on the outer peripheral portion of the opening of the yoke 41 and fixed with an adhesive. Next, an elastic spacer 43 is fixed in an annular groove formed in the coupler 22. Then, the voice coil bobbin 26 around which the voice coil is wound is fixed to the engaging portion 22a of the coupler 22 with an adhesive, and the dustproof damper 45 is mounted on the mounting portion 22e of the dustproof damper 45. Next, the damper fixed to the yoke 41 in a state where the voice coil portion of the voice coil bobbin 26 fixed to the coupler 22 is loosely inserted into the gap formed by the inner periphery of the yoke 41 and the outer periphery of the plate 32. The magnetic circuit portion 12 of the exciter 17 is configured by screwing 44 to the mounting seat portion 22c of the coupler 22 with screws.

  Next, the bracket 49 is fixed to a predetermined position on the vibration member 46 (for example, the back side of the ceiling plate of the automobile). Then, the screw 49a of the bracket 49 fixed to the vibration member 46 is screwed into the screw hole 22b formed in the coupler 22 of the magnetic circuit unit 12 of the exciter 17 and fastened, whereby the interior direct drive speaker is configured. Is done.

As described above, according to the magnetic circuit unit 12 of the exciter 17 according to the third embodiment of the present invention, by providing the recess 32a on the magnet fixing surface side of the plate 32, the thickness of the magnet 37 is increased by the amount of the recess 32a. Can be thicker. That is, since the volume of the magnet 37 is increased, the magnetic flux density can be increased, so that the power can be increased. In addition, the height of the magnetic circuit portion 12 of the exciter 17 can be reduced in size by the amount corresponding to the concave portion 32a as compared with the conventional exciter having the same power.
(Embodiment 4)
Embodiment 4 of the present invention will be described with reference to FIG. FIG. 5 is a schematic sectional view showing the magnetic circuit structure of the exciter according to the fourth embodiment of the present invention. In the fourth embodiment, a part of the third embodiment is changed. The same components as those in the third embodiment are denoted by the same reference numerals, description thereof is omitted or simplified, and the changed points are mainly described.

  Reference numeral 13 denotes a magnetic circuit unit 13 (a repulsive magnetic circuit in which magnets having the same polarity are arranged above and below the plate and a magnetic flux is formed in a horizontal direction by a repelling magnetic field) for an interior direct drive speaker, as shown in FIG. Consists of a coupler 22, a voice coil bobbin 26 around which a voice coil is wound, a plate 33, magnets 38 and 39, a yoke 41, a damper 44, a spacer 43, a dustproof damper 45, a bracket 49 fixed to a vibration member (vibration plate) 46, and the like. Has been.

  The magnet 38 is a disk-shaped permanent magnet and has an outer diameter dimension slightly smaller than the outer diameter dimension of the plate 33. The magnet 39 is a disk-shaped permanent magnet whose outer diameter is such that it fits into the recess 33a of the plate 33, and whose thickness is substantially the same as the depth of the recess 33a.

  Here, a part of the assembly of the magnetic circuit unit 13 of the exciter 18 will be briefly described. First, the magnet 39 is fitted into the recess 33a of the plate 33 and fixed with an adhesive. Next, the plate 33 and the magnet 38 are fixed with an adhesive in a concentric state. Then, the end surface of the fixed magnet 38 is fixed to the bottom surface inside the yoke 41. At this time, the yoke 41 is fixed so that there is a uniform gap between the inner periphery of the yoke 41 and the outer periphery of the plate 33 and the magnet 38. Since the subsequent assembly order (configuration) is the same as that of the third embodiment, a description thereof will be omitted.

  As described above, according to the magnetic circuit unit 13 of the exciter 18 according to the fourth embodiment of the present invention, the magnet 38 is fixed to the upper surface of the plate 33 and the magnet 39 is fixed to the concave portion 33a, so that the magnet is fixed to the concave portion 33a. Since the volume of the magnet increases by 39, the magnetic flux density can be increased and the power can be increased. Further, since the plate 33 is provided so as to be sandwiched between the two magnets 38 and 39, a repulsive magnetic circuit is formed and the exciter 18 is strengthened, so that the sound quality can be improved.

It is the schematic which shows the magnetic circuit structure of the exciter of Embodiment 1 of this invention. It is a schematic sectional drawing which shows the magnetic circuit structure of the exciter of Embodiment 2 of this invention. It is a schematic sectional drawing which shows the magnetic circuit structure of the exciter partially different from this Embodiment 2. It is a schematic sectional drawing which shows the magnetic circuit structure of the exciter of Embodiment 3 of this invention. It is a schematic sectional drawing which shows the magnetic circuit structure of the exciter of Embodiment 4 of this invention. It is a schematic sectional drawing which shows the magnetic circuit structure of the exciter of a prior art. It is a schematic plan view which shows the damper of an exciter.

Explanation of symbols

10, 11, 12, 13 ... Magnetic circuit portion 15, 16, 17, 18 ... Exciter 20, 21, 22, 23 ... Coupler 20a ... Circular protrusion 20c ... Chamfer 20f, 21e 22c: Mounting seat 21a: Screw hole protrusion 26 ... Voice coil bobbins 30, 31, 32, 33 ... Plates 35, 36, 37, 38, 39 ... Magnets 40, 41 ..Yoke 43 ... Spacer 44 ... Damper 45 ... Dustproof damper 47 ... Vibrating member 50 ... Screw

Claims (6)

A drive side in which a magnetic field space is formed by a magnet and a plate inside a bottomed cylindrical yoke, and a coupler provided so that a voice coil wound around a voice coil bobbin is positioned in the magnetic field space. In the magnetic circuit structure of the exciter held elastically by the damper,
The exciter magnetic circuit structure is characterized in that the exciter is provided with proximity means that can vibrate in the vicinity of or overlapping with an opposing portion of the drive side and the coupler side during driving. The proximity means includes a screw seat surface protrusion of the coupler provided to fix the exciter to the edge of the hole of the plate formed in an annular shape and the bracket fixed to the vibration member with a screw. 2. The exciter magnetic circuit structure according to claim 1, wherein the peripheral portion is chamfered. The proximity means includes a screw hole protrusion of a coupler provided to fix the exciter to the vibration member, and a recess into which the screw hole protrusion fits into the opposing surface of the plate formed in a disc shape. The magnetic circuit structure of the exciter according to claim 1, wherein: The exciter magnetic circuit structure according to claim 3, wherein the plate is formed with a through hole into which the screw hole protrusion of the coupler is loosely fitted. 2. The exciter magnet according to claim 1, wherein the magnet contact surface of the plate is provided with a recess into which the magnet is fitted, and the magnet has a volume corresponding to the recess. Circuit structure. The exciter according to claim 5, wherein a concave portion into which another magnet is fitted is provided on the back side of the magnet contact surface of the plate, and the plate is provided so as to sandwich the plate between two magnets. Magnetic circuit structure.

Images