JP3918529B2 - Speaker and manufacturing method thereof - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a speaker and a manufacturing method thereof. More specifically, the present invention relates to a super high frequency reproduction speaker having a very high high frequency reproduction limit frequency fh and excellent frequency characteristics without a peak dip, and a simple and inexpensive manufacturing method thereof.
[0002]
[Prior art]
In recent years, music sources have been digitized rapidly in the audio-related industry. Under such circumstances, expansion of the reproduction frequency band is also demanded for speakers. For example, in order to expand the reproduction frequency band in a high frequency reproduction speaker, it is necessary to further shift the high frequency reproduction limit frequency fh to the high frequency side. As means for shifting fh to the high frequency side, typically, the weight of the vibration system is reduced, the rigidity of the diaphragm is increased, and the like.
[0003]
Here, in a high frequency reproduction speaker, a metal foil such as beryllium, aluminum or titanium, a non-metallic high elastic material such as ceramic, graphite or diamond is used as a diaphragm material. However, such a material can increase the rigidity of the diaphragm, but the weight of the vibration system becomes heavy, so that fh cannot be sufficiently shifted to the high frequency side after all. Further, since the high-rigidity material has small internal loss due to vibration, there is a problem that peak dip is likely to occur in the frequency characteristics. Furthermore, such a highly rigid material is very expensive and impractical.
[0004]
On the other hand, in ultra-high frequency reproduction of fh or more, drive disturbance is likely to occur at the joint between the diaphragm and the voice coil, resulting in poor drive transmission efficiency from the voice coil and a sharp drop in sound pressure. Sometimes. In order to avoid such a problem, it is necessary to increase the strength of the joint between the diaphragm and the voice coil. However, in the conventional speaker, the strength of the joint is insufficient. This is because it has a shape including a wide flat portion as shown in FIG. 8 in order to improve the adhesion operability. Furthermore, the strength of the joint portion cannot be sufficiently increased with a material normally used for a high frequency reproduction speaker.
[0005]
Further, from the viewpoint of the manufacturing method, in order to shift fh to the high frequency side, the center of the voice coil and the amount of adhesive applied are important. This is because the driving disturbance of the joint portion between the diaphragm and the voice coil is likely to occur in the ultra high range of fh or more.
[0006]
In the conventional manufacturing method, as shown in FIG. 9, a voice coil holding jig in which a diaphragm is placed on a diaphragm holding jig, an adhesive is applied to a voice coil joint portion of the diaphragm, and the voice coil is mounted. Is fitted into the diaphragm holding jig to bond the diaphragm and the voice coil.
[0007]
However, in this method, there is a dimensional difference between the inner diameter D1 of the diaphragm holding jig and the outer diameter D2 of the voice coil holding jig, and a dimensional difference between the inner diameter D3 of the voice coil mounting portion of the voice coil holding jig and the voice coil inner diameter. This makes it difficult to center the diaphragm and the voice coil. As a result, a gap failure may occur when the voice coil is inserted into the magnetic gap of the magnetic circuit. Further, since the diaphragm is merely placed on the diaphragm holding jig, it may be assembled with the diaphragm tilted.
[0008]
Further, in the conventional manufacturing method, when the voice coil holding jig with the voice coil attached is fitted into the diaphragm holding jig, the voice coil lead wire pulled out from the jig is pressed with a finger as shown in FIG. The operation is performed so that does not fall. However, according to such an operation, there is a problem that a voice coil having a particularly narrow winding width is likely to fall off from the voice coil holding jig. In addition, according to the conventional method, it is necessary to produce a corresponding voice coil holding jig whenever the height of the voice coil changes, which is disadvantageous in terms of cost.
[0009]
As described above, there is a strong demand for a high-frequency reproduction speaker that satisfies both the fh and peak dip problems and a simple and inexpensive manufacturing method thereof.
[0010]
[Problems to be solved by the invention]
The present invention has been made in order to solve the above-described conventional problems. The object of the present invention is to have a very high high-frequency reproduction limit frequency fh and an excellent frequency characteristic without a peak dip. An object of the present invention is to provide a super high frequency reproduction speaker and a simple and inexpensive manufacturing method thereof.
[0011]
[Means for Solving the Problems]
The speaker of the present invention includes a diaphragm, a voice coil that drives the diaphragm, and a magnetic circuit that forms a magnetic field that intersects the voice coil, and a joint portion of the diaphragm with the voice coil is substantially The shape does not include a flat portion.
[0012]
In a preferred embodiment, the diaphragm has a cone-dome shape, the cone-side half apex angle is 10 ° or more, and the dome-side half apex angle is 27 ° or more.
[0013]
In a preferred embodiment, the diaphragm is made of a material selected from the group consisting of polyetheretherketone, polyetherimide, polyimide, and crystalline polystyrene.
[0014]
In a preferred embodiment, the voice coil is a bobbinless voice coil.
[0015]
According to another aspect of the present invention, a method for manufacturing a speaker is provided. The manufacturing method includes a step of arranging a voice coil holding jig having a convex portion having a cross-sectional shape corresponding to the cross-sectional shape of the voice coil and a guide so that the convex portion faces upward; Arranging the voice coil on the voice coil holding jig as described above; forming the diaphragm into a predetermined shape; and preparing a diaphragm holding jig mounting member including a suction portion and a guide hole Providing a diaphragm holding jig having a suction portion, having a shape corresponding to the shape of the diaphragm, and adapted to be attached to the diaphragm holding jig mounting member; Contacting the diaphragm with the diaphragm holding jig and the diaphragm holding jig mounting member; passing the guide hole of the diaphragm holding jig mounting member through the guide of the voice coil holding jig; And the voice And a step of bonding the yl.
[0016]
In a preferred embodiment, the voice coil holding jig further includes a height adjusting unit in the guide.
[0017]
The operation of the present invention will be described below.
According to the present invention, the joint portion of the diaphragm with the voice coil has a shape that does not include a substantially flat portion, so that the strength of the joint portion is improved and the drive transmission efficiency from the voice coil is improved. The problem that the pressure characteristic rapidly decreases is solved. Further, since it is not necessary to take a means of increasing the thickness of the material in order to improve the strength of the diaphragm, there is an advantage that even a thin material can be used sufficiently.
[0018]
In a preferred embodiment, the diaphragm has a cone-dome shape, the cone-side half apex angle is 10 ° or more, and the dome-side half apex angle is 27 ° or more. By setting the half apex angle in such a range, a peak dip in the sound pressure frequency characteristic can be prevented, and a speaker having a flat characteristic can be obtained.
[0019]
According to the speaker manufacturing method of the present invention, the voice coil holding jig is arranged so that the convex part of the voice coil holding jig having the convex part faces upward, and the voice coil is adapted to the convex part. , Voice coil centering becomes precise and easy. As a result, it is possible to satisfactorily join the diaphragm and the voice coil having a shape in which the joining portion does not include a substantially flat portion. Furthermore, according to this manufacturing method, the diaphragm and the voice coil are joined by passing the guide hole of the diaphragm holding jig mounting member through the guide of the voice coil holding jig. Since the positional relationship between the guide and the convex portion is fixed, the problem of centering failure due to dimensional error for each speaker to be assembled is prevented. In addition, according to this manufacturing method, the diaphragm is joined to the voice coil in a state in which the diaphragm is in close contact with the diaphragm holding jig (that is, the diaphragm and the jig are in close contact with each other with high accuracy). The risk of bonding to the voice coil when tilted is extremely small.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited to these embodiments.
[0021]
FIG. 1 is a schematic cross-sectional view for explaining a speaker according to a preferred embodiment of the present invention, and FIG. 2 is a schematic cross-sectional view of a diaphragm and a voice coil included in the speaker of FIG. As shown in FIG. 1, the speaker 10 includes a diaphragm 1, a voice coil 2 that drives the diaphragm 1, and a magnetic circuit 3 that forms a magnetic field that intersects the voice coil 2.
[0022]
The diaphragm 1 has a shape in which a joint portion with the voice coil 2 does not include a substantially flat portion. In the present invention, it is a necessary and sufficient requirement that the joint portion has a shape that does not substantially include a flat portion. By having such a shape, the strength of the joint portion is improved, the drive transmission efficiency from the voice coil is improved, and the problem that the sound pressure characteristic is rapidly deteriorated is solved. Here, “substantially does not include a flat portion” means that the width of the joint portion of the diaphragm 1 is substantially equal to or larger than the diameter of the winding of the voice coil 2 as shown in FIG. Say.
[0023]
The diaphragm 1 may have any suitable shape as long as it satisfies the requirement that the joint portion does not include a substantially flat portion, but preferably has a cone-dome shape. In this case, substantially not including a flat part means that the cone part and the dome part are connected with a practically minimum radius. By connecting in this way, the width of the joint portion of the diaphragm 1 becomes substantially equal to or larger than the diameter of the winding of the voice coil 2.
[0024]
In the case where the diaphragm 1 has a cone-dome shape, the half apex angle on the cone side is preferably 10 ° or more, and more preferably 13 ° to 37 °. The half apex angle on the dome side is preferably 27 ° or more, and more preferably 27 ° to 44 °. Here, as shown in FIG. 3, the “dome-side half apex angle” refers to a portion that is joined to the voice coil (that is, a vertex formed by the dome end and the cone end) in the vertical direction. The angle defined by the tangent line and the tangent at the dome end. “Cone side half apex angle” refers to an angle defined by the vertical line and the tangent at the cone end. By setting the half apex angles on the cone side and the dome side in such a range, a peak dip in the sound pressure frequency characteristic can be prevented, and a speaker having a flat characteristic can be obtained.
[0025]
Any appropriate material can be used as the material constituting the diaphragm 1, and specific examples of preferable materials include polyetheretherketone, polyetherimide, polyimide, and crystalline polystyrene. A more preferred material is crystalline polystyrene. This is because it is cheaper than metals and inorganic materials and has excellent strength.
[0026]
Preferably, the voice coil 2 is directly attached to the diaphragm 1 (that is, the bobbin and the flat joint portion of the diaphragm are not joined as in the prior art, but the coil is joined directly to the diaphragm. ing). Typically, the voice coil 2 is a bobbinless voice coil. This is because, by directly attaching the voice coil to the diaphragm, the bending due to driving becomes very small, and as a result, the divided vibration of the cone portion and the dome portion is reduced, and peak dip is prevented.
[0027]
Hereinafter, a preferable example of the manufacturing method of the speaker of the present invention will be described.
In the manufacturing method of the present invention, a voice coil holding jig 40 as shown in FIG. The voice coil holding jig 40 includes a convex portion 41 and a guide 42 having a cross-sectional shape (horizontal cross-sectional shape) corresponding to the cross-sectional shape (horizontal cross-sectional shape) of the voice coil. As long as the cross-sectional shape of the convex portion 41 corresponds to the cross-sectional shape of the voice coil, any appropriate shape can be adopted. For example, when the cross-sectional shape of the voice coil is circular, the cross-sectional shape of the convex portion 41 is circular. When the cross-sectional shape of the voice coil is elliptical, the cross-sectional shape of the convex portion 41 is elliptical. When the voice coil has a track shape, the protrusion 41 may have a track shape.
[0028]
Next, as shown in FIG. 4B, the voice coil 2 is arranged on the voice coil holding jig 40 arranged so that the convex portion 41 faces upward. Since the cross-sectional shape of the convex portion 41 of the voice coil holding jig 40 corresponds to the cross-sectional shape of the voice coil 2, the voice coil 2 is arranged in conformity with the convex portion 41. By arranging the voice coil holding jig 40 so that the convex portion 41 faces upward and adapting the voice coil 2 to the convex portion 41, the centering of the voice coil becomes precise and easy. As a result, it is possible to satisfactorily join the voice coil and the diaphragm having a shape in which the joining portion does not include a substantially flat portion as shown in FIG.
[0029]
On the other hand, as shown in FIG. 4C, a diaphragm holding jig mounting member 43 and a diaphragm holding jig 44 are prepared. The diaphragm holding jig attachment member 43 includes a suction part 45 and a guide hole 46. The diaphragm holding jig 44 has a shape corresponding to the shape of the diaphragm and is adapted to be attached to the diaphragm holding jig attachment member 43. Further, the diaphragm holding jig 44 includes a suction portion 47 as in the diaphragm holding jig mounting member 43. The suction part 47 of the diaphragm holding jig 44 communicates with the suction part 45 of the diaphragm holding jig attachment member 43 when the diaphragm holding jig 44 and the diaphragm holding jig attachment member 43 are fitted. Typically, the diaphragm holding jig 44 and the diaphragm holding jig mounting member 43 can be screwed.
[0030]
Here, as shown in FIG. 4C, the diaphragm 1 formed into a predetermined shape (in this embodiment, a cone-dome shape is illustrated) is disposed on the diaphragm holding jig 44, and the diaphragm 1 The diaphragm holding jig 44 in which is disposed is adapted to the diaphragm holding jig mounting member 43. In such a state, the diaphragm holding jig 44 and the diaphragm holding jig mounting member 43 are screwed and sucked from the outside of the diaphragm holding jig mounting member 43, whereby the diaphragm 1, the diaphragm holding jig 44, and the diaphragm are sucked. The holding jig attaching member 43 is brought into close contact with the holding jig attaching member 43. Here, an adhesive is applied to the joint portion of the diaphragm 1 by any appropriate method. Any appropriate adhesive can be used as the adhesive, but typically, a thermosetting resin adhesive (for example, an epoxy resin adhesive), a photocurable adhesive (for example, an epoxy-modified acrylate resin adhesive). UV curable adhesive).
[0031]
Next, as shown in FIG. 4 (d), the guide hole 46 of the diaphragm holding jig mounting member 43 is inserted into the voice coil while the diaphragm 1, the diaphragm holding jig 44, and the diaphragm holding jig mounting member 43 are in close contact with each other. The diaphragm 1 and the voice coil 2 are brought into close contact with each other through the guide 42 of the holding jig 40. The diaphragm 1 and the voice coil 2 are firmly bonded by curing the adhesive by any appropriate method according to the type of the adhesive. Thus, according to the present invention, the diaphragm and the voice coil are joined through the guide. Since the positional relationship between the guide 42 and the convex portion 41 is fixed, the problem of centering failure due to a dimensional error for each speaker to be assembled is prevented. Further, since the diaphragm 1 is joined to the voice coil 2 in a state where the diaphragm 1 is attracted and adhered to the diaphragm holding jig 44 (that is, the diaphragm 1 and the jig 44 are adhered with high precision), the diaphragm 1 is tilted. The risk of bonding with the voice coil in the state is extremely reduced.
[0032]
In a preferred embodiment, the voice coil holding jig 40 includes a height adjustment unit 47 in the guide 42. The height adjusting unit 47 can be, for example, rings having different thicknesses. The thickness of the ring can vary corresponding to the height of the voice coil. By providing such a height adjustment unit, since a common voice coil holding jig can be used even if the dimensions of the voice coil are changed, it is possible to greatly contribute to a reduction in manufacturing cost.
[0033]
Thereafter, the diaphragm and the voice coil are attached to a magnetic circuit, a frame or the like by any appropriate method to complete the speaker.
[0034]
【Example】
Example 1
A speaker having a diameter of 27 mm was produced by the following procedure. First, a voice coil holding jig provided with a convex portion was arranged so that the convex portion was facing upward, and a bobbinless voice coil was fitted to the convex portion. The voice coil used was a LOK wire having a wire diameter of 0.07 mm. Note that any appropriate line type (for example, HAW line, SVW line) may be used as the voice coil.
[0035]
On the other hand, a diaphragm having a cone-dome shape was formed. The curve of the dome part was R5.5, the curve of the cone part was R4.5, and the voice diameter was 10.44 mm. Furthermore, the dome portion and the cone portion are connected with a practically minimum radius so that the joint portion between the diaphragm and the voice coil does not have a substantially flat portion. A crystalline polystyrene film was used as the diaphragm material. As a specific forming procedure, a film is preheated and softened at about 200 ° C. for 5 seconds using a far infrared heater, and then a mold having a predetermined shape (cone-dome shape in this embodiment) is used. Press molding was performed at a temperature of 85 to 95 ° C. and a pressing pressure of 80 to 100 kgf.
[0036]
Next, the diaphragm was sucked and fixed to the diaphragm holding jig and the diaphragm holding jig mounting member. Furthermore, using a two-component mixed gear pump type dispenser (manufactured by Japan Labor Co., Ltd.), a two-component epoxy resin (heat) is used for the joint portion (connection portion between the cone portion and the dome portion) of the diaphragm with the voice coil. 5 mg of a curable resin adhesive) was applied. Further, by passing the guide hole of the diaphragm holding jig mounting member through the guide of the voice coil holding jig, the diaphragm coated with the adhesive and the voice coil are brought into contact with each other and heated at 40 to 50 ° C. for 1 minute. The diaphragm and the voice coil were bonded. Finally, the bonded diaphragm and voice coil were attached to a magnetic circuit, frame, etc. to complete the speaker.
[0037]
The sound pressure frequency characteristics of the obtained speaker were simulated using the finite element method. The result is shown in FIG. 5 together with the result of Comparative Example 1 described later.
[0038]
(Comparative Example 1)
A speaker was manufactured in the same manner as in Example 1 except that the diaphragm had a shape including a wide flat portion as shown in FIG. The simulation similar to Example 1 was performed about the obtained speaker. The results are shown in FIG.
[0039]
As apparent from FIG. 5, the speaker of Example 1 has a much flatter sound pressure frequency characteristic than the speaker of Comparative Example 1, and the sound pressure drop in the ultra high range is small.
[0040]
(Example 2)
A speaker was produced in the same manner as in Example 1 except that a cone-dome shaped diaphragm as shown in FIG. Here, the curve of the dome portion is a composite shape of R1 and R20, the curve of the cone portion is R4, and the voice diameter is 10.44 mm. In this shape, the half apex angle on the cone side was 13 °, and the half apex angle on the dome side was 44 °. The simulation similar to Example 1 was performed about the obtained speaker. The results are shown in FIG. 7 together with the results of Example 3 and Comparative Examples 2 to 4 described later.
[0041]
(Example 3)
A speaker was manufactured in the same manner as in Example 2 except that a diaphragm having a cone-side half apex angle of 37 ° and a dome-side half apex angle of 42 ° was formed. Here, the curve of the dome portion was R7.5, and the curve of the cone portion was R4.5. The simulation similar to Example 2 was performed about the obtained speaker. The results are shown in FIG.
[0042]
(Comparative Example 2)
A speaker was manufactured in the same manner as in Example 2 except that a diaphragm having a half apex angle on the cone side of 48 ° and a half apex angle on the dome side of 48 ° was formed. Here, the curve of the dome portion was R10.5, and the curve of the cone portion was R4.5. The simulation similar to Example 2 was performed about the obtained speaker. The results are shown in FIG.
[0043]
(Comparative Example 3)
A speaker was manufactured in the same manner as in Example 2 except that a diaphragm having a cone-side half apex angle of 35 ° and a dome-side half apex angle of 4 ° was formed. Here, the curve of the dome portion is a composite shape of R10.5 and R4.5, and the curve of the cone portion is R4.5. The simulation similar to Example 2 was performed about the obtained speaker. The results are shown in FIG.
[0044]
(Comparative Example 4)
A speaker was manufactured in the same manner as in Example 2 except that a diaphragm having a cone-side half apex angle of 0 ° and a dome-side half apex angle of 43 ° was formed. Here, the curve of the dome portion was R20, and the curve of the cone portion was R4.15. The simulation similar to Example 2 was performed about the obtained speaker. The results are shown in FIG.
[0045]
As is clear from FIG. 7, the speakers of Examples 2 and 3 have a flat sound pressure frequency characteristic, and there is little decrease in sound pressure in the ultrahigh frequency range. On the other hand, the sound pressure of the speaker of Comparative Example 2 rapidly decreases in a band greater than 60 kHz. In the speaker of Comparative Example 3, a peak dip is observed at 20 to 40 kHz, and the sound pressure in a band exceeding 70 kHz is reduced. The speaker of Comparative Example 4 shows a large peak dip at 50-60 kHz.
[0046]
Example 4
Use a two-component UV curing adhesive (World Lock No. 836A / B, manufactured by Kyoritsu Chemical Industry Co., Ltd.) as an adhesive, and irradiate a diffusion metal halide lamp (irradiation intensity 100 mW / cm ² ) for 10 to 15 seconds. A speaker was produced in the same manner as in Example 1 except that it was cured.
[0047]
【The invention's effect】
As described above, according to the present invention, by using the diaphragm having a shape in which the joint portion with the voice coil does not include a substantially flat portion, the diaphragm has a very high high-frequency reproduction limit frequency fh, and Thus, it is possible to obtain a super high frequency reproduction speaker having excellent frequency characteristics without a peak dip. According to the manufacturing method of the present invention, a voice coil holding jig provided with a guide and a diaphragm holding jig mounting member provided with a guide hole and capable of sucking and adhering the diaphragm through the diaphragm holding jig are used. Thus, the speaker as described above can be easily and inexpensively manufactured.
[Brief description of the drawings]
FIG. 1 is a schematic cross-sectional view for explaining a speaker according to a preferred embodiment of the present invention.
2 is a schematic cross-sectional view of a diaphragm and a voice coil included in the speaker of FIG.
FIG. 3 is a schematic cross-sectional view for explaining in detail the relationship between the diaphragm and the voice coil in the speaker of the present invention.
FIGS. 4A to 4D are schematic views for explaining a speaker manufacturing method according to a preferred embodiment of the present invention.
FIG. 5 is a graph showing simulation results of sound pressure frequency characteristics for the speaker of the example of the present invention and the speaker of the comparative example.
FIG. 6 is a schematic cross-sectional view for explaining a diaphragm shape in the speaker of the embodiment of the present invention.
FIG. 7 is a graph showing simulation results of sound pressure frequency characteristics for the speaker of the example of the present invention and the speaker of the comparative example.
FIG. 8 is a schematic cross-sectional view showing a diaphragm shape in a conventional speaker.
FIG. 9 is a schematic view showing a conventional method for manufacturing a speaker.
FIG. 10 is a schematic view showing a conventional method for manufacturing a speaker.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Diaphragm 2 Voice coil 3 Magnetic circuit 10 Speaker 40 Voice coil holding jig 43 Diaphragm holding jig attachment member 44 Diaphragm holding jig

Claims (2)

Arranging a voice coil holding jig provided with a convex portion having a cross-sectional shape corresponding to the cross-sectional shape of the voice coil and a guide so that the convex portion faces upward;
Placing the voice coil on the voice coil holding jig so as to fit the convex portion;
Forming a diaphragm into a predetermined shape;
Preparing a diaphragm holding jig mounting member having a suction part and a guide hole;
Providing a diaphragm holding jig having a suction portion, having a shape corresponding to the shape of the diaphragm, and adapted to be attached to the diaphragm holding jig mounting member;
A step of bringing the diaphragm and the diaphragm holding jig and the diaphragm holding jig mounting member into close contact with each other by suction; and
A method of manufacturing a speaker, comprising: passing the guide hole of the diaphragm holding jig attachment member through the guide of the voice coil holding jig to bond the diaphragm and the voice coil.   The manufacturing method according to claim 1, wherein the voice coil holding jig further includes a height adjusting unit in the guide.

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