JP2006121422A - Loudspeaker - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a loudspeaker suitable for a low profile in which rolling phenomenon is suppressed without adversely affecting a magnetic efficiency and an amplitude amount. <P>SOLUTION: The loudspeaker 21 is provided in which a voice coil 24 wound on a bobbin 23 is arranged in a magnetic gap G surrounded by a yoke 32, a diaphragm 25 is arranged at an outside of the radial direction of the bobbin 23 in a tapered shape, and an inner circumferential edge of the diaphragm 25 supports a base end of the bobbin 23, wherein a notch part 32a is provided in an outer wall of the yoke 32, an annular spacer 28 made of a magnetic material is joined with the notch part 32a, each of inner circumferential edges of first and second dampers 29, 30 is fixed to both end faces of the annular spacer 18 in its axial line direction, and each of the inner circumferential edges of the first and second dampers 29, 30 is fixed to the diaphragm 25 to support the diaphragm 25 by both the dampers 29, 30. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an electrodynamic loudspeaker, and more particularly to a loudspeaker that is arranged in a tapered shape so that a diaphragm surrounds a voice coil.

  Conventionally, there is a configuration in which the diaphragm is arranged around the bobbin by fixing the base end of the bobbin to the inner peripheral edge of the small diameter with the large diameter side of the tapered diaphragm facing the magnetic circuit side, Therefore, a speaker is known that is reduced in thickness by suppressing the overall height (for example, see Patent Document 1).

  FIG. 2 is a cross-sectional view showing a conventional example of this type of speaker. The speaker 1 shown in FIG. 1 includes a magnetic circuit 2 having a magnetic gap G, a voice coil 4 wound around the tip of a bobbin 3 and disposed in the magnetic gap G, cone paper formed in a tapered shape, and the like. A diaphragm 5 having an inner peripheral edge bonded and fixed to the base end of the bobbin 3, a frame 7 fixed to the magnetic circuit 2 and supporting the outer peripheral edge of the diaphragm 5 via an edge portion 6, A damper 8 whose peripheral edge is fixed to the upper end surface of the magnetic circuit 2 in the figure and whose outer peripheral edge is fixed to the diaphragm 5 is provided with a dustproof cap 9 that is attached to the bobbin 3.

  In the speaker 1, a diaphragm 5 disposed in a tapered shape on the radially outer side of the bobbin 3 is supported by a damper 8 and an edge portion 6 so as to freely vibrate. The proximal end is supported. The magnetic circuit 2 includes an annular magnet 10 magnetized in the axial direction, a yoke 11 having a pole piece portion 11a, and an outer peripheral surface of the pole piece portion 11a placed on the magnet 10. And a plate-like yoke 12 forming a magnetic gap G.

In the speaker 1 configured as described above, when a voice current is supplied to the voice coil 4 via a lead wire (not shown), the voice coil 4 is vibrated by electromagnetic force, so that the diaphragm 5 is driven via the bobbin 3. To vibrate. The speaker 1 is arranged so that the diaphragm 5 surrounds the bobbin 3 by directing the large diameter side of the tapered diaphragm 5 to the magnetic circuit 2 side. Dimensions are suppressed.
JP-A-4-111597 (first page, Fig. 4)

  The above-described conventional speaker 1 is thinned by arranging the diaphragm 5 around the bobbin 3 in a tapered shape. However, the diaphragm 5 is supported only by one damper 8. Therefore, there is a problem that the rolling phenomenon in which the bobbin 3 is inclined with respect to the vibration direction is likely to occur. In order to suppress the rolling phenomenon, a speaker having a configuration in which a damper is disposed in front of the diaphragm 5 (upward in the drawing) and the inner peripheral edge of the diaphragm 5 is supported by the damper has been proposed. Then, since the sound wave radiated | emitted from the diaphragm 5 will produce distortion by the influence of a damper, it is unpreferable.

  Therefore, it is possible to suppress the rolling phenomenon by adopting a double damper structure in which the diaphragm is supported by two dampers. In such a double damper structure, the inner peripheral edge of both dampers is used as the yoke outer wall of the magnetic circuit. For example, if the spacer member is fixed to the outer wall of the yoke without changing the shape of the magnetic circuit, the damper length is shortened by the plate thickness of the spacer member, and the amplitude of the diaphragm is increased. In addition, if the thickness of the yoke outer wall is reduced in order to ensure the damper length, a new problem arises that the magnetic flux is saturated and a magnetic circuit with poor magnetic efficiency is formed.

  The present invention has been made in view of such a state of the art, and an object thereof is to provide a speaker suitable for thinning that can suppress a rolling phenomenon without adversely affecting magnetic efficiency and amplitude. is there.

  The present invention eliminates a problem that is a concern when a double damper structure is adopted by providing a notch on the yoke outer wall of the magnetic circuit and joining an annular spacer made of a magnetic material to the notch. It was. That is, a first damper having an inner peripheral edge portion fixed to one end surface in the axial direction of the annular spacer and a second damper having an inner peripheral edge portion fixed to the other end surface in the axial direction of the annular spacer. The outer peripheral edge portions of the first and second dampers are fixed to the diaphragm, and the diaphragm is supported by both dampers.

  The speaker according to the present invention employs a double damper structure in which the first damper and the second damper support the diaphragm disposed so as to surround the bobbin, so that the overall height dimension can be suppressed. In addition, the bobbin rolling phenomenon can be reliably suppressed. In addition, the inner peripheral edge of both dampers is fixed to an annular spacer made of a magnetic material, and the annular spacer is fitted into a notch provided on the outer wall of the magnetic circuit yoke. As a result, even if the thickness of the yoke outer wall is reduced, the magnetic efficiency of the magnetic circuit is not adversely affected, and the damper lengths of both dampers are not sacrificed. As a result, it is possible to realize a speaker suitable for thinning that can suppress the rolling phenomenon without adversely affecting the magnetic efficiency and the amplitude.

  In the present invention, the voice coil wound around the bobbin, the magnetic circuit having a magnetic gap surrounded by the yoke, and the inner peripheral edge of the bobbin is disposed at the base end of the bobbin. And a frame that is integrated with the magnetic circuit and supports an outer peripheral edge of the diaphragm via an edge portion, and energizes the voice coil disposed in the magnetic gap. In the speaker in which the diaphragm is driven by the above, a notch is provided on the outer wall of the yoke, and an annular spacer made of a magnetic material is joined to the notch, and the axial spacers are connected to both end faces in the axial direction. The inner peripheral edges of the first damper and the second damper are fixed, and the outer peripheral edges of the first and second dampers are fixed to the diaphragm so that the diaphragm is supported by both dampers. Ni It was.

  According to the speaker configured in this way, the double damper structure can be used to effectively suppress the bobbin rolling phenomenon and to fix the inner peripheral edge portions of the first and second dampers. The annular spacer is made of a magnetic material, and this annular spacer is joined to the cutout portion of the yoke outer wall of the magnetic circuit, so that the magnetic efficiency of the magnetic circuit is not adversely affected and the required damper length is reduced. It is possible to prevent the amplitude amount of the diaphragm from being restricted.

  In the above configuration, it is preferable that the first damper and the second damper are set to substantially the same damper length, and in this way, the bobbin rolling phenomenon can be more effectively suppressed.

  An embodiment will be described with reference to the drawings. FIG. 1 is a half sectional view of a speaker according to an embodiment of the present invention.

  A speaker 21 shown in the figure includes a magnetic circuit 22 having a magnetic gap G, a voice coil 24 wound around a tip portion of a bobbin 23, a diaphragm 25 made of cone paper or the like formed into a tapered shape, and a magnetic circuit. A frame 27 that is fixed to the circuit 22 and supports the outer peripheral edge of the diaphragm 25 via an edge 26, an annular spacer 28 made of a magnetic material, and an inner peripheral edge on one end surface in the axial direction of the annular spacer 28 ( A first damper 29 having an outer peripheral edge fixed to the outer peripheral edge of the diaphragm 25 and an inner peripheral edge fixed to the other axial end surface (lower end face in the figure) of the annular spacer 28. The outer peripheral edge portion is roughly constituted by a second damper 30 fixed to the outer peripheral edge portion of the diaphragm 25 and a dustproof cap 31 that is attached to the bobbin 23 so as to surround the diaphragm 25. To Placing the Jo, it has a speaker is suppressed overall height dimension.

  The magnetic circuit 22 includes a yoke 32 formed into a bottomed cylindrical shape, a disk-shaped magnet 33 magnetized in the axial direction, and a disk-shaped pole piece 34 placed on the magnet 33. A magnetic gap G is formed between the inner peripheral surface of the yoke 32 and the outer peripheral surface of the pole piece 34. An annular notch 32a is provided on the outer wall on the opening end side of the yoke 32, and an annular spacer 28 is fitted into the notch 32a. However, as long as a notch for the annular spacer 28 is provided on the outer wall of the yoke surrounding the magnetic gap G, the configuration of the magnetic circuit 22 can be appropriately selected.

  The base end portion (the upper end in the figure) of the bobbin 23 is bonded and fixed to the inner peripheral edge portion of the diaphragm 25. The diaphragm 25 is supported by the first and second dampers 29 and 30 and the edge portion 26 so as to freely vibrate. ing. The voice coil 24 wound around the bobbin 23 is connected to a lead wire (not shown). When a voice current is passed through the lead wire, the voice coil 24 vibrates due to electromagnetic force. As a result, the bobbin 23 vibrates and the inner peripheral edge of the diaphragm 25 is driven, so that the diaphragm 25 vibrates and radiates sound waves.

  The annular spacer 28 is formed by forming a magnetic material such as iron or powder metallurgy into an annular shape, and the annular spacer 28 is fitted into the cutout portion 32 a of the yoke 32 and fixedly bonded. The annular spacer 28 is a member having both a spacer function for positioning the inner peripheral edge portions of the first and second dampers 29 and 30 and a yoke function for complementing the yoke 32 of the magnetic circuit 22.

  The damper lengths of the first damper 29 and the second damper 30 are set to be substantially equal, and both the inner peripheral edge portions of both the dampers 29 and 30 are bonded and fixed to the upper and lower end surfaces of the annular spacer 28 to thereby The inner peripheral edge portions of the dampers 29 and 30 are positioned and fixed in a state of being separated by the height dimension of the annular spacer 28. Further, both dampers 29 and 30 are disposed so as to be inclined so that their outer peripheral edges approach each other, and these both outer peripheral edges are integrated and fixedly bonded to the outer peripheral edge of the diaphragm 25. As a result, the outer peripheral edge of the diaphragm 25 can be supported by the edge part 26 and the first and second dampers 29 and 30 from three different directions, so that it is supported by the inner peripheral edge of the diaphragm 25. The effect of suppressing the rolling phenomenon of the bobbin 23 is increasing.

  As described above, the speaker 21 according to the present embodiment has a thin structure in which the overall height dimension is suppressed by disposing the tapered diaphragm 25 so as to surround the bobbin 23. Since the double damper structure in which the plate 25 is supported by the first damper 29 and the second damper 30 positioned and fixed by the annular spacer 28 is employed, the rolling phenomenon of the bobbin 23 can be reliably suppressed. . Further, in this speaker 21, the thickness of the outer wall of the yoke 32 is thin at the notch 32 a in order to fit the annular spacer 28, but the annular spacer 28 is made of a magnetic material and is part of the yoke. Since the magnetic circuit 22 can function, the magnetic efficiency of the magnetic circuit 22 is not much different from that in the case where the yoke 32 does not have the notch 32a. That is, even if the outer wall of the yoke 32 is partially thinned by providing the notch 32a, the annular spacer 28 made of a magnetic material supplements the yoke function, so that the magnetic flux is saturated and the magnetic efficiency is increased. There is no risk of undesirably decreasing. Further, since the inner peripheral edge portions of the first and second dampers 29 and 30 are fixed in the notch portion 32a of the yoke 32, the speaker 21 has a configuration in which an annular spacer 28 is provided. It is not necessary to sacrifice the damper length (the length in the radial direction) of the dampers 29 and 30, so that the amplitude amount of the diaphragm 25 is not restricted.

  In the above-described embodiment, in order to effectively suppress the rolling phenomenon of the bobbin 23, the damper lengths of the first damper 29 and the second damper 30 are set to be approximately equal. The rolling phenomenon can also be suppressed by attaching individual dampers to appropriate portions of the diaphragm 25.

It is a half cross-sectional view of a speaker according to an embodiment of the present invention. It is sectional drawing of the speaker which concerns on a prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 21 Speaker 22 Magnetic circuit 23 Bobbin 24 Voice coil 25 Diaphragm 26 Edge part 27 Frame 28 Circular spacer 29 1st damper 30 2nd damper 32 Yoke 32a Notch part G Magnetic gap

Claims (2)

A voice coil wound around a bobbin, a magnetic circuit having a magnetic gap surrounded by a yoke, and a vibration that is arranged in a taper shape on the outer side in the radial direction of the bobbin and whose inner peripheral edge supports the base end of the bobbin A diaphragm integrated with the magnetic circuit and supporting an outer peripheral edge of the diaphragm via an edge portion, and the diaphragm is energized by energizing the voice coil disposed in the magnetic gap. In a speaker driven by
A notch is provided in the outer wall of the yoke, and an annular spacer made of a magnetic material is joined to the notch, and the inner ends of the first damper and the second damper are arranged on both end faces in the axial direction of the annular spacer. A loudspeaker characterized in that the peripheral edge portion is fixed and the outer peripheral edge portions of the first and second dampers are fixed to the diaphragm, and the diaphragm is supported by both dampers.   The speaker according to claim 1, wherein the first damper and the second damper are set to have substantially the same damper length.

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