JP5977978B2 - Speaker device - Google Patents

Description

  The present invention relates to a center cap and a speaker device.

  It is known to provide a function of improving the high frequency characteristics of reproduced sound to a center cap (dust cap) installed at the center of the diaphragm as a dust-proof measure inside a speaker device such as a voice coil.

  For example, in Patent Document 1, a thin film member, which is a member different from the cap body that covers the center hole of the diaphragm, is attached to the back surface of the cap body to constitute a center cap for the speaker device.

JP 2010-273066 A

  However, the thin film member of Patent Document 1 has a very thin thickness of about 10 μm to 150 μm. For this reason, the shaping | molding operation | work and sticking operation | work of a thin film member involve a complicated operation | work. Therefore, in patent document 1, the workability | operativity in the assembly process of a speaker apparatus will be impaired. Moreover, in Patent Document 1, thin film members having various dimensions and shapes must be prepared in accordance with the shapes of the diaphragm and the center cap, and the versatility is poor.

  Further, in Patent Document 1, since the thin film member is a member that is not used in the normal assembly process of the speaker device, it is possible to avoid an increase in member cost accompanying the introduction of the thin film member, an increase in cost accompanying an increase in man-hours, and the like. Can not.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to solve the above-described problems. That is, the present invention provides a center cap and a speaker device that can suppress cost increase while improving workability and versatility, and that can improve high-frequency characteristics.

A speaker device according to claim 1 of the present invention includes a diaphragm, a voice coil, a magnetic circuit,
A center cap installed on a surface of the diaphragm in the sound radiation direction, and the center key
The speaker device has a ring-shaped adhesive that is in contact with only the opposite surface on the surface opposite to the surface in the sound radiation direction of the cap .

It is the schematic of the speaker apparatus which concerns on one Embodiment of this invention. It is the schematic of the center cap which concerns on one Embodiment of this invention. It is a figure which shows the output characteristic of the reproduction sound in the speaker apparatus which concerns on one Embodiment of this invention. It is a figure which shows the output characteristic in the high sound range of the reproduced sound in the speaker apparatus which concerns on one Embodiment of this invention. It is a figure which shows the other example in the shape of the adhesive agent fixed to the center cap which concerns on one Embodiment of this invention.

Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.
FIG. 1 is a schematic diagram of a speaker device 1 according to an embodiment of the present invention. In FIG. 1, the longitudinal cross-sectional structure fractured | ruptured in the sound radiation direction of the speaker apparatus 1 is shown.
The speaker device 1 shown in FIG. 1 has a low-profile, substantially frustoconical shape with the sound emission direction as the central axis. In FIG. 1, the axial direction of the speaker device 1 is the vertical direction of the paper surface, and the radial direction of the speaker device 1 is the horizontal direction of the paper surface, the near side, and the depth direction. In FIG. 1, the sound emission direction of the speaker device 1 is assumed to be upward. The same applies to FIG.
The speaker device 1 includes at least a magnetic circuit 10, a voice coil 20, a frame 30, a damper 40, a diaphragm 50, and a center cap 100.

The magnetic circuit 10 forms a magnetic gap G that can accommodate the voice coil 20, and supplies magnetic flux necessary for vibration of the voice coil 20.
The magnetic circuit 10 includes a plate 11, a yoke 12, and a magnet 13. The magnetic circuit 10 has a structure in which a yoke 12, a magnet 13, and a plate 11 are laminated in order from the bottom to the top.
The magnetic circuit 10 of FIG. 1 is a so-called external magnetic type speaker circuit magnetic circuit, but may be an internal magnetic type.

The plate 11 forms a magnetic path of the magnetic circuit 10 and one end of the magnetic gap G.
The plate 11 is made of a magnetic material such as iron and has a substantially annular shape with a central axis in the axial direction. The inner diameter of the plate 11 formed in a substantially annular shape is larger than the outer diameter of the voice coil 20. The outer diameter of the plate 11 is the same as or smaller than the outer diameter of the magnet 13. The thickness of the plate 11 is substantially uniform.

  The lower surface of the plate 11 is magnetically joined to one pole side (for example, the S pole side) of the magnet 13. The magnetic flux that has flowed out of the magnet 13 passes through the plate 11. The inner peripheral surface of the plate 11 faces the outer peripheral surface of a later-described center pole portion 12b constituting the yoke 12 and forms one end of the magnetic gap G.

The yoke 12 forms the magnetic path of the magnetic circuit 10 and one end of the magnetic gap G.
The yoke 12 has a bottom plate portion 12a and a center pole portion 12b.
The bottom plate portion 12a is formed in a substantially disc shape with the central axis in the axial direction. The outer diameter of the bottom plate portion 12 a formed in a substantially disc shape is the same as or smaller than the outer diameter of the magnet 13. The thickness of the bottom plate portion 12a is substantially uniform.
The center pole portion 12b is formed in a substantially cylindrical shape with the center of the bottom plate portion 12a as a base end and the center axis extending upward along the axial direction. The outer diameter of the center pole portion 12b formed in a substantially cylindrical shape is smaller than the outer diameter of the voice coil bobbin 21 described later. The height of the center pole portion 12b is substantially uniform.
The bottom plate portion 12a and the center pole portion 12b are formed using a magnetic material such as iron and are integrally formed.

  The upper surface of the bottom plate portion 12a is magnetically joined to the other pole side of the magnet 13 (the side different from the magnetic pole joined to the plate 11, for example, the N pole side). The magnetic flux flowing out from the magnet 13 passes through the yoke 12. The outer peripheral surface of the center pole portion 12 b faces the inner peripheral surface of the plate 11 substantially in parallel and forms one end of the magnetic gap G.

  The inner peripheral surface of the plate 11 and the outer peripheral surface of the center pole portion 12b face each other substantially in parallel at a predetermined interval. The predetermined interval is larger than the radial thickness of the voice coil 20 and the voice coil bobbin 21. The magnetic circuit 10 forms a magnetic gap G in the gap between the inner peripheral surface of the plate 11 and the outer peripheral surface of the center pole portion 12b defined by the predetermined interval. The magnetic gap G has a substantially cylindrical shape with a central axis in the axial direction, and accommodates the voice coil 20 and the voice coil bobbin 21.

The magnet 13 supplies a magnetic flux to the magnetic circuit 10, particularly to the magnetic gap G.
The magnet 13 is formed of a permanent magnet such as a ferrite-based magnet, a samarium-cobalt-based magnet, or a neodymium-based magnet, and the central axis is formed in a substantially annular shape in the axial direction. The outer diameter of the magnet 13 formed in a substantially annular shape is approximately the same as or larger than the outer diameter of the plate 11 and the bottom plate portion 12a. The inner diameter of the magnet 13 is approximately the same as or larger than the inner diameter of the plate 11. The inner peripheral surface of the magnet 13 does not contact the voice coil 20 disposed in the magnetic gap G. The thickness of the magnet 13 is substantially uniform. The magnet 13 is sandwiched between the plate 11 and the bottom plate portion 12a with the respective central axes being overlapped.

  The upper surface and the lower surface of the magnet 13 have a pair of magnetic poles. The magnetization direction of the magnet 13 is substantially parallel to the axial direction. The upper surface of the magnet 13 having one magnetic pole (for example, the S pole) is magnetically bonded to the lower surface of the plate 11. The lower surface of the magnet 13 having the other magnetic pole (for example, N pole) is magnetically joined to the upper surface of the bottom plate portion 12 a constituting the yoke 12.

If the lower surface of the magnet 13 is an N pole, the magnetic flux flowing out from the lower surface of the magnet 13 passes through the bottom plate portion 12a and the center pole portion 12b and flows out into the magnetic gap G. The magnetic flux flowing out to the magnetic gap G passes through the plate 11 and flows into the upper surface of the magnet 13.
In this way, the magnetic circuit 10 supplies magnetic flux into the magnetic gap G.

The voice coil 20 is a driving source for vibration of the diaphragm 50.
The voice coil 20 is wound around the outer periphery of a voice coil bobbin 21 whose central axis has a substantially cylindrical shape in the axial direction. The central axis of the voice coil 20 is the axial direction and is substantially the same as the central axis of the voice coil bobbin 21. The place where the voice coil 20 is wound is the end of the voice coil bobbin 21 on the lower side (the direction opposite to the sound radiation direction). The height at the center of the winding width of the voice coil 20 (the axial position at the center of the winding width) is substantially the same as the height at the central thickness of the plate 11 (the axial position at the center of the thickness).
The winding direction of the voice coil 20 is substantially orthogonal to the direction (axial direction) in which the central axis of the voice coil bobbin 21 formed in a substantially cylindrical shape extends.
A diaphragm 50 and a damper 40 are connected to the outer peripheral surface of the upper end (sound radiation direction side) of the voice coil bobbin 21.

A center pole portion 12b is disposed on the radially inner side of the voice coil bobbin 21 formed in a substantially cylindrical shape. The inner peripheral surface of the voice coil bobbin 21 and the outer peripheral surface of the center pole portion 12b face each other substantially in parallel with a predetermined interval. A plate 11 and a magnet 13 are disposed outside the voice coil 20 in the radial direction. The outer peripheral surface of the voice coil 20 and the inner peripheral surfaces of the plate 11 and the magnet 13 face each other substantially in parallel with a predetermined interval. The central axes of the voice coil 20 and the voice coil bobbin 21 and the central axes of the center pole portion 12b, the plate 11, and the magnet 13 are substantially the same position.
That is, the voice coil bobbin 21 around which the voice coil 20 is wound is accommodated in the magnetic gap G so as to be capable of vibrating in the axial direction. The vibration direction of the voice coil bobbin 21 is substantially orthogonal to the direction of the magnetic flux supplied to the magnetic gap G and the direction of the audio current supplied to the voice coil 20.

The voice coil 20 is connected to a speaker amplifier (not shown) via a lead wire. A voice current is supplied to the voice coil 20 from the speaker amplifier. When an audio current is supplied, the voice coil 20 receives an electromagnetic force due to the interaction between the magnetic flux of the magnetic gap G and the current. The voice coil 20 receiving the electromagnetic force vibrates in the axial direction within the magnetic gap G using the electromagnetic force as a driving force. The voice coil 20 that vibrates in the axial direction vibrates the diaphragm 50 connected to the voice coil bobbin 21 in the axial direction.
In this way, the voice coil 20 converts the supplied audio current into mechanical vibration and gives the diaphragm 50 an axial driving force.

The frame 30 is a skeleton of the speaker device 1 and supports the magnetic circuit 10, the damper 40, and the diaphragm 50.
The frame 30 is formed in a substantially frustoconical shape with a central axis in the axial direction, and is hollow inside. The lower bottom portion 31 and the upper bottom portion 32 of the frame 30 formed in a substantially frustoconical shape are substantially parallel to each other and substantially perpendicular to the axial direction. The side wall 33 of the frame 30 has a shape in which the outer periphery of the lower bottom portion 31 is a base end and the tip extends in a reverse taper shape toward the upper bottom portion 32 in a cross-sectional view. The lower bottom portion 31, the upper bottom portion 32, and the side wall portion 33 have a substantially uniform thickness, and are integrally formed using a metal material or a resin material.

  The lower bottom portion 31 of the frame 30 has a substantially disc-shaped through hole 31a at a substantially center. The outer diameter of the through hole 31 a is substantially the same as the inner diameter of the plate 11. The voice coil bobbin 21 is disposed in the through hole 31a. The lower surface of the lower bottom portion 31 is joined to the upper surface of the plate 11. By this joining, the frame 30 supports the magnetic circuit 10.

The side wall 33 of the frame 30 has a stepped portion 33a at the same height as the end on the upper side (sound radiation direction side) of the voice coil bobbin 21. The step portion 33a forms a flat surface with the axial direction as a normal line. A damper 40 is joined to the flat surface of the step portion 33a.
By this joining, the frame 30 supports the damper 40.

  A tip of the side wall 33 of the frame 30 opens upward. On the outer periphery of the open end of the side wall 33, a substantially annular upper base 32 extending outward in the radial direction in a sectional view is formed. The upper surface of the upper bottom portion 32 is joined to an edge portion 52 described later of the diaphragm 50. By this joining, the frame 30 supports the diaphragm 50.

The damper 40 fixes the voice coil bobbin 21 to the frame 30. The damper 40 regulates the vibration in the radial direction of the voice coil 20 and holds the vibration center in the axial direction.
The damper 40 is formed in a substantially annular shape with a central axis in the axial direction. The inner peripheral edge portion of the damper 40 formed in a substantially annular shape is joined to the outer peripheral surface of the end portion on the upper side (sound radiation direction side) of the voice coil bobbin 21. The outer peripheral edge portion of the damper 40 is joined to the step portion 33 a of the side wall portion 33 constituting the frame 30.
By these joining, the damper 40 fixes the voice coil bobbin 21 to the frame 30. At this time, since the damper 40 has corrugation, the voice coil bobbin 21 is elastically fixed to the frame 30 and the vibration of the voice coil 20 wound around the voice coil bobbin 21 is regulated and controlled.

The diaphragm 50 mechanically vibrates in the axial direction and emits sound. The diaphragm 50 is connected to the voice coil bobbin 21. The diaphragm 50 is interlocked with the axial vibration of the voice coil 20 wound around the voice coil bobbin 21.
The diaphragm 50 is formed in a substantially truncated cone shape with a central axis in the axial direction using a metal material, a resin material, a fiber material, or a mixed material thereof.
The diaphragm 50 includes a vibration part 51 and an edge part 52. The vibration part 51 and the edge part 52 are integrally formed.

The vibration part 51 is a main body part of the diaphragm 50, and can vibrate in the axial direction. The diaphragm 50 radiates sound waves generated by the vibration of the vibration unit 51 upward.
The vibration part 51 has a shape extending in a reverse taper shape upward in a sectional view, and is formed at the center of the vibration plate 50. Although the vibration part 51 of FIG. 1 has a shape in which the cross-sectional view extends upward in a reverse taper shape, the vibration part 51 may have a substantially parabolic shape, a substantially multistage curved shape, or the like.

The inner peripheral side of the vibration part 51 has an opening 51a having a substantially circular shape in plan view at a substantially center. The outer diameter of the opening 51 a is substantially the same as the outer diameter of the voice coil bobbin 21. The voice coil bobbin 21 is disposed in the opening 51a. The inner peripheral edge portion of the vibrating portion 51 is joined to the outer peripheral surface of the end portion on the upper side (sound radiation direction side) of the voice coil bobbin 21.
By this joining, the diaphragm 50 plate is interlocked with the vibration in the axial direction of the voice coil 20 wound around the voice coil bobbin 21. The location where the inner peripheral edge of the vibrating portion 51 is joined to the voice coil bobbin 21 is located above the location where the damper 40 is joined to the voice coil bobbin 21.

The edge part 52 fixes the diaphragm 50 to the frame 30. The edge part 52 regulates and controls the vibration of the diaphragm 50 together with the damper 40. The edge portion 52 blocks the sound on the back side of the diaphragm 50 (the side opposite to the sound emission direction).
The edge portion 52 includes a curved portion 52a having a curved shape that is convex upward in cross-sectional view and a flat portion 52b that is substantially linear in cross-sectional view. The curved portion 52 a is formed along the outer periphery of the vibration portion 51. The flat part 52b is formed along the outer periphery of the curved part 52a. The temporary surface of the flat portion 52 b is joined to the upper surface of the upper bottom portion 32 of the frame 30.
By this joining, the edge portion 52 fixes the diaphragm 50 to the frame 30. At this time, the edge part 52 has the curved part 52a, thereby elastically fixing the diaphragm 50 to the frame 30, and regulating / controlling the vibration of the diaphragm 50.

The center cap 100 prevents intrusion of dust or the like into the speaker device and improves frequency characteristics in the high sound range.
The center cap 100 is installed on the upper surface of the vibration part 51 so as to cover the opening 51a of the vibration part 51 constituting the diaphragm 50 from above.
The center cap 100 is formed in a substantially disk shape with the central axis in the axial direction. In the present embodiment, an example is shown in which the shape of the center cap 100 is formed in a dome shape with the central axis protruding upward in the axial direction. The sound emission direction of the center cap 100 is above the axial direction. The upper surface of the center cap 100 is a surface located on the sound radiation direction side, and this surface is a sound radiation surface 101 in this embodiment. The lower surface of the center cap 100 is a surface positioned on the side opposite to the surface positioned on the sound emission direction side, and this surface is a back surface 102 in the present embodiment.

The center cap 100 in FIG. 1 has a substantially parabolic shape that is convex upward in sectional view, but may be in a substantially semicircular shape, a substantially semi-elliptical shape, a substantially triangular shape, a substantially multi-stage arc shape, or the like in a sectional view. The center cap 100 in FIG. 1 has a substantially circular shape in plan view, but may be deformed in accordance with the shape of the upper surface of the vibration part 51 on which the center cap 100 is installed.
The center cap 100 is formed using a metal material, a resin material, a fiber material, or a mixed material thereof. The material of the center cap 100 may be the same material as the diaphragm 50 or may be a material having a larger internal loss than the diaphragm 50.

  FIG. 2 is a schematic view of the center cap 100 according to an embodiment of the present invention. FIG. 2A is a perspective view of the center cap 100 as viewed from the sound emission surface 101 side. FIG. 2B is a perspective view of the center cap 100 as viewed from the back surface 102 side. FIG. 2C is a plan view seen from the back surface 102 side of the center cap 100. FIG. 2D is a diagram showing an outline of a longitudinal cross-sectional structure in which the center cap 100 of FIG.

  As shown in FIG. 2A, the sound emitting surface 101 of the center cap 100 is formed in a dome shape that is convex in the sound emitting direction (upward) and whose central axis is the axial direction. The planar shape of the sound emitting surface 101 has a substantially circular shape, and the cross-sectional shape has a substantially parabolic shape. The back surface 102 of the center cap 100 has the same shape as the sound emission surface 101.

As shown in FIG. 2B, an adhesive 110 is fixed to the back surface 102 of the center cap 100.
The adhesive 110 is, for example, a rubber-based adhesive such as silicone rubber or butyl rubber. Preferably, the adhesive 110 is a butyl rubber adhesive.
The shape of the adhesive 110 is formed in a substantially annular shape, and has a closed loop shape. The adhesive 110 having a substantially annular shape has a central axis substantially the same as the axial direction. That is, the central axis of the adhesive 110 is substantially the same as the central axis of the center cap 100 and the voice coil bobbin 21.
As shown in FIG. 2C, the planar shape of the adhesive 110 is substantially concentric with the center cap 100 having a substantially circular shape in plan view. That is, the planar centroid of the adhesive 110 and the planar centroid of the center cap 100 are at substantially the same position.
What is necessary is just to design the magnitude | size of the external shape of the adhesive agent 110 suitably in the magnitude | size which a high sound range characteristic improves. For example, the diameter of the adhesive 110 may be approximately half the outer diameter of the center cap 100.
What is necessary is just to design the thickness of the adhesive agent 110 suitably in the magnitude | size which a high sound range characteristic improves. For example, as shown in FIG. 2D, the maximum thickness t2 of the adhesive 110 may be made larger than the minimum thickness t1 of the center cap 100. In other words, the minimum thickness t1 of the center cap 100 in the sound emission direction may be smaller than the maximum thickness t2 of the adhesive 110 fixed to the back surface 102 in the sound emission direction. Examples of suitable numerical values include an example where t1 = 0.3 mm and t2 = 1.0 mm.

  The adhesive 110 is a separate adhesive from the adhesive used to join the center cap 100 and other members constituting the speaker device 1. The adhesive 110 is in contact with only the back surface 102 of the center cap 100.

For example, after the adhesive used for installing the center cap 100 on the vibration part 51 of the diaphragm 50 is applied to the center cap 100 or the vibration part 51, the adhesive is cured in contact with both. As a result, this adhesive is in contact with both the center cap 100 and the vibrating portion 51.
Similarly, the adhesive used for joining the upper surface of the upper end of the voice coil bobbin 21 to the back surface 102 of the center cap 100 is applied to the back surface 102 or the voice coil bobbin 21 and then in contact with both. Cured. As a result, this adhesive is in contact with both the back surface 102 and the voice coil bobbin 21.
On the other hand, after the adhesive 110 is placed on the back surface 102 of the center cap 100, it is cured as it is without coming into contact with other members. The adhesive 110 is an adhesive that contacts only the back surface 102 of the center cap 100.

The speaker device 1 having the center cap 100 to which the adhesive 110 is fixed exhibits the following output characteristics. The speaker device 1 is a speaker device capable of reproducing a so-called full-range frequency band.
FIG. 3 is a diagram showing output characteristics of reproduced sound in the speaker device 1 according to the embodiment of the present invention.
The vertical axis in FIG. 3 indicates the output sound pressure level of the speaker device 1, and the horizontal axis in FIG. 3 indicates the frequency expressed on a logarithmic scale.
The curve in FIG. 3 shows the output sound pressure frequency characteristic of the speaker device 1.

In FIG. 3, different characteristics are shown for each fixing condition of the adhesive 110. The fixing conditions of the adhesive 110 are as shown in conditions A to D shown in Table 1. All conditions other than the fixing condition of the adhesive 110 are the same.
In the curve of FIG. 3, the solid line indicates the result under Condition A, the one-dot chain line indicates the condition B, the two-dot chain line indicates the condition C, and the broken line indicates the result under Condition D.
Note that the shape of the adhesive 110 in the condition A is the shape shown in FIG. The shape of the adhesive 110 under the conditions B and C is the shape shown in FIG.

In the frequency band from around 20 Hz in the low sound range to around 2 kHz in the mid sound range, the output sound pressure level shows a substantially flat transition after rising. In this frequency band, the same transition is shown for each of conditions A to D.
In the frequency band from about 2 kHz to about 6 kHz in the middle sound range, the output sound pressure level shows a transition that repeats peak dip. In this frequency band, although the amplitude of the peak dip is different for each of the conditions A to D, the same transition is shown.
In a frequency band from around 6 kHz in the middle sound range to around 20 kHz in the high sound range, the output sound pressure level shows a transition in which a large amplitude peak dip is repeated. In this frequency band, different transitions are shown for each of the conditions A to D.

FIG. 4 is a diagram showing output characteristics of the reproduced sound in the high frequency range in the speaker device 1 according to the embodiment of the present invention.
The graph of FIG. 4 is an enlarged graph of the frequency band from 6 kHz in the middle sound range to 20 kHz in the high sound range in the graph shown in FIG. 3.
It can be seen that the following transitions are shown for each of conditions A to D in the frequency band from around 6 kHz in the middle sound range to around 20 kHz in the high sound range.

The case where the adhesive 110 is fixed (conditions A to C) and the case where the adhesive 110 is not fixed (condition D) are compared.
The heights of the resonance peaks a to c at the high frequency resonance frequency of the conditions A to C are lower than the height of the resonance peak d at the high frequency resonance frequency of the condition D.
The half widths of the resonance peaks a to c of the conditions A to C are larger than the half width of the resonance peak d of the condition D.
That is, by adhering the adhesive 110 to the back surface 102 of the center cap 100, it is possible to suppress the resonance peak at the high-frequency resonance frequency and widen the frequency range of the high-frequency range.
Such a transition is due to the fact that the adhesive 110 has a larger internal loss than the diaphragm 50, and the center cap 100 to which the adhesive 110 is fixed can obtain a higher vibration absorbing action.

The case where the material of the adhesive 110 is butyl rubber (Condition B) and the case of silicone rubber (Condition C) are compared.
The height of the resonance peak b of the condition B is lower than the height of the resonance peak c of the condition C. The half width of the resonance peak b of the condition B is larger than the half width of the resonance peak c of the condition C.
That is, regarding the material of the adhesive 110, butyl rubber can suppress the resonance peak more than silicone rubber, and can further widen the frequency band of the high sound range.
Such transition is due to the fact that butyl rubber has a larger internal loss than silicone rubber, and the center cap 100 to which butyl rubber is fixed as the adhesive 110 can obtain a higher vibration absorbing action.

The case where the adhesive 110 is fixed in a substantially annular shape (condition A) is compared with the case where the adhesive 110 is substantially circular (conditions B and C) and the case where the adhesive 110 is not fixed (condition D).
The resonance peak a of condition A has two peaks, while the resonance peak b of condition B has one peak. The resonance peak c of the condition C and the resonance peak d of the condition D also have one peak.
The height of the resonance peak a in condition A is lower than the height of the resonance peak b in condition B. The half width of the resonance peak a in condition A is larger than the half width of the resonance peak b in condition B.
That is, with respect to the fixed shape of the adhesive 110, the resonance peak can be further suppressed and the frequency range of the high sound range can be further expanded in the case of the substantially annular shape rather than the substantially disk shape.
When the adhesive 110 is fixed in a substantially annular shape, the transition is such that the natural frequency of the center cap 100 is different between the radial inner side and the radial outer side of the adhesive 110 fixing region, and the resonance peak appears. This is due to the fact that it was distributed in two. It is considered that the height of each peak is reduced and the half-value width is also increased due to the dispersion of the resonance peaks into two.

  In the hearing evaluation under the conditions A to D, the following evaluation results were obtained. That is, in condition D, a sense of distortion and miscellaneous taste were observed in the high sound range, while in conditions A to C, there was no sense of distortion and mischief in the high sound range, and improvement was achieved. Furthermore, in the conditions A and B, the omission in the high sound range is good, which is further improved than the condition C. In particular, in condition A, the gorgeousness in the high sound range was added, and the condition B was further improved.

  In the present embodiment, the adhesive 110 that contacts only the back surface 102 is fixed to the center cap 100 when the high frequency range characteristics are improved by the center cap 100. For bonding the center cap 100 and the diaphragm 50, an adhesive is generally used. The adhesive application step at this time is a step of applying the adhesive to the joint surface with the diaphragm 50 with the back surface 102 of the center cap facing upward. This application process is one of the usual assembly processes of the speaker device. For this reason, the process of fixing the adhesive 110 to the back surface 102 can be performed as a part of the process of applying the adhesive used for joining to the diaphragm 50, which requires introduction of new members and processes and complicated work. do not do. Therefore, in the present embodiment, it is possible to provide the center cap 100 that can improve the high-frequency characteristics and is excellent in workability.

Further, the adhesive 110 is inexpensive and its fixed shape can be easily changed. For this reason, even if the shape and dimensions of the center cap 100 are variously changed, it is only necessary to change the fixing shape of the adhesive 110. Therefore, in the present embodiment, it is possible to provide the center cap 100 that can improve the high sound range characteristics, is inexpensive, and has excellent versatility.
Therefore, in the present embodiment, it is possible to provide the center cap 100 that can suppress the increase in cost and improve the high sound range characteristics while ensuring workability and versatility. Moreover, the speaker apparatus 1 carrying such a center cap 100 can be provided.

  Further, in this embodiment, the center cap 100 is formed in a substantially disk shape, and the adhesive 110 is fixed in a substantially annular shape shown in FIG. 2A or a substantially annular shape shown in FIG. It was formed in a disk shape. The central axis of the adhesive 110 and the central axes of the center cap 100 and the voice coil bobbin 21 are made substantially the same. For this reason, in this embodiment, the vibration displacement of the center cap 100 is not unevenly distributed in the radial direction. Therefore, in this embodiment, the effects of suppressing the resonance peak in the high sound range and expanding the frequency band by the adhesive 110 can be obtained without being biased over the entire center cap 100. Moreover, the resonance which generate | occur | produces when the vibration displacement of the center cap 100 is unevenly distributed in radial direction can be suppressed.

  The above embodiment is an example of a preferred embodiment of the present invention, but the present invention is not limited to this, and various modifications or changes can be made without departing from the scope of the invention. .

  In the present embodiment, examples of the fixing shape of the adhesive 110 include the substantially annular shape shown in FIG. 2A and the substantially disk shape shown in FIG. Other examples of the fixing shape of the adhesive 110 include a substantially elliptical ring shape shown in FIG. 5B and a substantially polygonal ring shape shown in FIG. In addition, as a fixing shape of the adhesive 110, as shown in FIG. 5D, the closed loop adhesive 110 may be fixed to two or more places. In any case, the central axis of the adhesive 110 is substantially the same as the central axis of the center cap 100 and the voice coil bobbin 21. In other words, the planar centroid of the adhesive 110 and the planar centroids of the center cap 100 and the voice coil bobbin 21 are at substantially the same position.

DESCRIPTION OF SYMBOLS 1 Speaker apparatus 10 Magnetic circuit 11 Plate 12 Yoke 13 Magnet 20 Voice coil 21 Voice coil bobbin 30 Frame 40 Damper 50 Diaphragm 100 Center cap 101 Sound radiation surface 102 Back surface 110 Adhesive

Claims (11)

A diaphragm, a voice coil, a magnetic circuit, and a cell installed on the surface of the diaphragm in the sound radiation direction.
A cap,
The speaker device having a ring-shaped adhesive that is in contact with only the surface on the opposite side of the surface of the center cap in the sound radiation direction. The adhesive is larger than the material forming the surface of the center cap in the sound radiation direction
The speaker device according to claim 1, which has an internal loss . The adhesive, the speaker device according to claim 1 or 2 having an adhesive rubber. The speaker device according to claim 1, wherein the adhesive includes butyl rubber.
. The speaker device according to any one of claims 1 to 4 , wherein a material forming the surface of the center cap in the sound radiation direction is a fiber material . In the sound radiation direction, the minimum thickness of the center cap is the maximum thickness of the adhesive.
The speaker device according to any one of claims 1 to 5, wherein the speaker device is smaller . The adhesive, spin according to any one of claims 1 to 6 having at least a substantially annular shape
Car equipment . The adhesive according to any one of claims 1 to 6 , wherein the adhesive has at least a substantially elliptical ring shape .
Peaker device . The adhesive according to any one of claims 1 to 6, wherein the adhesive has at least a substantially polygonal ring shape .
Peaker device . The center cap has a substantially disk shape,
And centroid of the planar shape before Symbol center cap, the centroid of the planar shape of the adhesive, substantially the same
The speaker device according to any one of claims 7 to 9, wherein the speaker device is located at the position . The voice coil is connected to the diaphragm via a voice coil bobbin,
The voice coil bobbin has a substantially cylindrical shape,
The adhesive has a substantially annular shape,
Wherein a central axis of the voice coil bobbin and the center axis of the adhesive according to claim 1 which is substantially the same
The speaker apparatus in any one of thru | or 6 and 10.