JP3292276B2 - Voice coil structure, voice coil mounting method and device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

TECHNICAL FIELD The present invention relates to a microphone,
The present invention relates to a voice coil structure such as a speaker, and a method and an apparatus for mounting a voice coil on a bobbin of the voice coil.
In particular, the structure of a voice coil in which a bobbin is formed in a substantially U-shaped section with an inner bobbin and an outer bobbin portion, and an air core coil is inserted in the groove, and an air core coil is formed in the groove of the bobbin. The present invention relates to a mounting method for mounting and a device therefor.

[0001]

2. Description of the Related Art As an acoustic diaphragm such as a microphone and a speaker, as shown in FIG. 9, there is an integral diaphragm 1 in which a cone diaphragm 11 and a chamber 12 are integrally formed by a film, and a bobbin of a voice coil is provided in the chamber. 1
2 and an outer bobbin portion 13b integrally formed with the cone diaphragm 11 are formed into a substantially "U" -shaped cross section, and an air-core coil is formed in a U-shaped groove of the bobbin. The bobbin-less coil 2 is mounted.

A conventional voice coil structure and a method of mounting an air core coil on a bobbin as described above will be described. As shown in an enlarged cross-sectional view of FIG. 9, the inner bobbin portion 13a and the outer bobbin portion 13b are formed. Of the U-shaped groove L
Are provided with clearances 1a and 1b so that the inner diameter 2a and the outer diameter 2b of the air core coil 2 can be easily inserted, and the air core coil 2 is inserted into the groove and fixed with an adhesive h.

[0003] Generally, the voice coil is very easily deformed by external pressure, and this tendency is particularly strong since the air core coil 2 is bobbin-less. At present, the work of mounting the air-core coil 2 in the U-shaped groove is basically performed by hand, and is most easily deformed when the air-core coil 2 is inserted. The clearances la and lb are set large enough to express it as dropping rather than inserting.

After dropping the air core coil 2 into the gap L,
The gap h is filled with the adhesive h to fix the air-core coil 2. As described above, since the clearances 1a and 1b are large, the clearances 1a and 1b are filled with the adhesive. Is disadvantageous, and the wall pressure of the bobbin becomes larger than the effective wall thickness of the coil.
The air-core coil 2 in which the wire diameter of the coil wire is reduced by a and 1b is set.

Accordingly, the input resistance is inferior to the case where the air-core coil 2 having a large wire diameter corresponding to the clearances 1a and 1b is mounted. Further, since the inner diameter portion 2a and the outer diameter portion 2b of the air core coil 2 are not in close contact with the inner bobbin portion 13a and the outer bobbin portion 13b, there is a disadvantage that transmission loss from the air core coil 2 occurs. In terms of the magnetic efficiency of the magnetic gap, the clearances 1a,
The presence of 1b is extremely disadvantageous, and it goes without saying that it is preferable that such clearances 1a and 1b do not exist in the speaker design.

In order to cope with such a defect, as a method of minimizing the clearances 1a and 1b, a method of mounting the air-core coil 2 using a coil mounting jig as shown in FIG. 10 is adopted. . The coil mounting jig includes a diaphragm receiving jig 3 having a supporting portion for supporting an edge portion and a bobbin portion of the integrated diaphragm 1 for disposing the integrated diaphragm 1 at a predetermined position; And a coil jig 4 for holding the air-core coil 2 without deformation when inserting the air core coil 2 into the gap L. The coil jig 4 is provided with a coil insertion slider 4a. The plate receiving jig 3 and the coil jig 4 are set so that their center lines are aligned, that is, centered.

As shown in FIG. 10, the integrated vibration plate 1 is disposed on the vibration plate receiving jig 3 and the air-core coil 2 is disposed on the coil jig 4, and the coil jig 4 is lowered to mount the air-core coil 2. The bobbin is inserted into the gap L of the U-shaped groove, and the slider 4a
To slide the air core coil 2 to a predetermined depth of the U-shaped groove and mount it.

[0008]

However, even if a coil mounting jig as shown in FIG. 10 is used, the dimensional tolerance of the diaphragm receiving jig 3 and the coil jig 4 and the dimensional tolerance of the integrated diaphragm 1 will be described. In consideration of the above, a certain clearance must be provided, and if the clearance is set to be narrow to the limit of the dimensional tolerance, when the air core coil 2 is inserted into the U-shaped groove, the air core coil 2 and the inner bobbin portion 13a are formed. In addition, a contact portion is generated in the outer bobbin portion 13b, and the contact portion is inserted with friction.

Therefore, the friction causes peeling of the insulating layer of the coil wire or the like, and the air-core coil 2 and the inner bobbin 1
This causes local deformation of the outer bobbin portion 3a and the outer bobbin portion 13b, causing a rare short circuit and deformation of the integrated diaphragm 1, resulting in an increase in a defective rate. FIG.
Even if a coil mounting jig as shown in (1) is used, a minimum clearance must be provided in order to insert the air core coil 2, and it is impossible to eliminate the clearance itself.

FIG. 12 shows a configuration of a general voice coil vc for a speaker, which is manufactured by directly winding a coil wire wc around a bobbin b. Therefore, the coil c
Has a structure in which the coil c is in close contact with the bobbin b, so that the propagation efficiency is generally improved when the coil c is in close contact with the bobbin b. However, when the air-core coil 2 is mounted on the integrated diaphragm 1 as described above, However, unlike the general speaker voice coil vc shown in FIG. 12, the air-core coil 2 cannot be mounted in close contact with the inner bobbin portion 13a and the outer bobbin portion 13b. It will be.

Also, since the integral diaphragm 1 is obtained by molding a film, the inner bobbin portion 13a and the outer bobbin portion 13b are slightly deformed and molded due to shrinkage or the like of the film. There is. For example, when formed from a para-oriented aromatic polyamide film, particularly a polyparaphenylene terephthalamide (hereinafter referred to as “PPTA”) film or the like, as shown in an enlarged sectional view of FIG. It is deformed and molded. When the molding die is placed upside down and molded, the inner bobbin portion 13a is deformed and molded. FIG. 11 is an exaggerated view for easy understanding, and although the dimensions are actually extremely small, when the air core coil 2 is inserted between the inner bobbin portion 13a and the outer bobbin portion 13b. Is an extremely alienating factor.

Accordingly, an object of the present invention is to solve the above-mentioned conventional drawbacks and to provide a voice coil bobbin having an inner bobbin portion and an outer bobbin portion formed into a substantially U-shaped cross section by film forming. In obtaining a voice coil structure in which an air-core coil is arranged and fixed with an adhesive, the voice coil can be easily attached to the air-core coil and can be closely attached to the inner bobbin portion and the outer bobbin portion. It is an object of the present invention to provide a mounting method, a device therefor, and an efficient voice coil structure obtained by the method.

[0013]

Means for Solving the Problems In order to solve the above-mentioned problems, a method of mounting a voice coil according to the present invention is characterized in that the bobbin of the voice coil is formed by film forming, and the cross section of the inner bobbin portion and the outer bobbin portion is approximately “ is formed on the U "shape, in the mounting method of the voice coil mounting the air core coil formed U-shaped groove from the" U "shaped portions of the both <br/> bobbin unit,
The bobbin is inserted into a mold having a substantially U-shaped cross-section so that the bobbin is fitted therein and having a suction hole formed in the groove, and a negative pressure is applied to the inside of the groove through the suction hole. Thereby, the inner bobbin portion and the outer bobbin portion are attracted to the groove peripheral surface side to form a clearance necessary for inserting the air core coil, and after the air core coil is inserted, the inside of the groove portion is returned to a positive pressure. In this method, the inner bobbin portion and the outer bobbin portion are brought into close contact with the air-core coil, and the groove is filled with an adhesive and fixed.

This method is particularly advantageous as a method for mounting a voice coil in an integral diaphragm type in which the inner bobbin is integrally molded with the chamber and the outer bobbin is integrally molded with the cone diaphragm.

Further, the voice coil mounting apparatus of the present invention is characterized in that an air core is provided in the U-shaped groove of the bobbin of the voice coil formed in the inner bobbin portion and the outer bobbin portion into a substantially U-shaped cross section by film forming. In a voice coil mounting device for mounting a coil, a suction hole for creating a negative pressure in the groove is formed in a mold provided with a groove having a substantially U-shaped cross section so that at least the bobbin is fitted. The mold is provided with a molding surface on which the inner bobbin portion integrally formed with the chamber and the outer bobbin portion formed integrally with the cone diaphragm are in close contact with each other.

By mounting the voice coil by the above-described method of mounting the voice coil using the voice coil mounting apparatus as described above, a voice coil structure in which the upper opening of the U-shaped groove is narrowed can be obtained. .

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIGS. 1 to 8. The same components as those of the prior art described with reference to FIGS. Detailed description is omitted.

The integrated diaphragm 1 is formed by integrally forming a cone diaphragm 11 and a chamber 12 with a film.
The bobbin of the voice coil includes an inner bobbin portion 13 a integrally formed with the chamber 12 and the cone diaphragm 11.
And the outer bobbin portion 13b formed integrally with the outer bobbin portion 13b.
An air-core coil 2 is formed in the U-shaped groove of the bobbin.
And fixed with an adhesive h.

The dimensions of each part of the integrated diaphragm 1 will be described. The integrated diaphragm 1 has a chamber 12 having an outer diameter of 11.70 mm at the center of a cone diaphragm 11 having an inner diameter of 25.4 mm. Is provided with a falling portion of 2 mm, that is, a diaphragm guide portion 11a, and a margin portion 11b having a width of 2 mm is provided horizontally from the lower end portion of the diaphragm guide portion 11a toward the outer periphery. And an inner peripheral portion of the cone diaphragm 11 and an outer peripheral portion of the chamber 12 (commonly called a neck).
Is provided with a gap L having a width of 0.22 mm,
2 from the outer periphery of the cone diaphragm 11 and the inner periphery of the cone diaphragm 11 respectively.
A falling portion of millimeters is provided, and the falling portion forms the inner bobbin portion 13a and the outer bobbin portion 13b, and connects the lower ends of the inner bobbin portion 13a and the outer bobbin portion 13b with a radius of 0.11 mm. The cross-section is approximately "U"
A bobbin in the shape of a letter is formed to have an integral structure.

The film for forming the integral diaphragm 1 is a polyimide film (referred to as "PI film") in the first embodiment, a PPTA film is used in the second embodiment, and the used PI film has a thickness of 25 mm. Micron, PPTA film is 25 microns thick.

The molding method is disclosed in Japanese Patent Application Laid-Open No.
The molding method described in JP-A-88853 is used, and a pair of rings for material holding, which are disposed opposite to each other on an upper mold side and a lower mold side of a molding apparatus that heats and molds a film body, are connected to the upper mold and the upper mold. In order to operate independently of the lower mold, the molded article is adsorbed to either the upper mold or the lower mold, and the ring on the adsorbed mold side is fixed, and the surface of the molded article is fixed. A removal jig having a surface shape corresponding to the shape is adsorbed and adsorbed to the molded product, and after removing the suction by the upper mold or the lower mold and moving the ejection jig, the jig is removed and fixed. It is a method of returning the ring which has been performed to the original position.

As a first embodiment, P
In order to mount the air-core coil 2 in a bobbin having a substantially U-shaped cross section of an integrated diaphragm 1 formed of an I-film, basically, a diaphragm receiving jig 3 and a coil jig 4 In the present invention, as shown in FIG. 1, the diaphragm receiving jig 3 is provided with a molding surface having a shape corresponding to the shape of the integrated diaphragm 1. That is, the support surface 3a corresponding to the cone diaphragm 11 and the chamber 12
When the integral diaphragm 1 is disposed on the diaphragm receiving jig 3, the inner bobbin portion 13 a and the outer bobbin portion 13 b have a “U” -shaped groove provided on the diaphragm receiving jig 3. 31.

In the embodiment, the dimensions of the groove 31 are 11.55 mm in inner diameter and 12.3 mm in outer diameter.
The outer diameter of the inner bobbin portion 13a (including the film thickness) and the outer diameter of the groove portion 31 and the outer portion of the outer bobbin portion 13b (including the film thickness) are each set to 0. Clearances lc and ld of 1 mm (0.05 mm on one side) or more are set. Thus, the inner bobbin portion 13a and the outer bobbin portion 13b of the integrated diaphragm 1 can be easily inserted into the groove 31 of the diaphragm receiving jig 3.

A suction hole 32 as shown in FIG. 1 is provided below the groove 31, and the suction hole 32 communicates with the outside of the jig through the hole 33. This hole 33 is a pipe P
Is connected to the valve B and the suction device S, and when the suction device S is operated and the valve B is opened, the groove 31 has a negative pressure. As shown in FIG. 3, the inner bobbin portion 13a and the outer bobbin portion 13b The inner bobbin 1 is attracted to the inner wall 31a and the outer wall 31b of the groove 31 from the position shown by the broken line.
The diameter of 3a is 11.6 mm or less, and the diameter of the outer bobbin portion 13b is 12.25 mm or more.

The air-core coil 2 is set to have a coil inner diameter of 11.7 mm and a wire diameter of 0.09 mm (a wire diameter including an insulating layer is 0.1 mm).
1mm) coil wire rod and outer diameter of approx.
2.14mm, winding width about 1.4mm, DC resistance about 3.4Ω
Air-core coil. The air-core coil 2 is set on the coil jig 4 as shown in FIG. 1, and the slider 4a is slid in the same manner as in the prior art, and inserted into the gap L between the inner bobbin portion 13a and the outer bobbin portion 13b as shown in FIG. And attach it.

At the time of insertion, 0.1 mm
Since there is a clearance 1a, 1b of at least 0.11 mm (0.055 mm on one side) on the side of the outer diameter 2b of the voice coil which is not less than (0.05 mm on one side), the inner diameter 2a of the coil, the outer diameter 2b of the coil, the inner bobbin portion 13a and the outer side are provided. Bobbin part 13b
Can be easily inserted without causing unnecessary friction.

After the air-core coil 2 is inserted, the valve B shown in FIG. 1 is closed and outside air is introduced into the groove 31, and the pressure of the groove 31 becomes the same as that of the atmosphere, so that the inner bobbin portion 13a and the outer bobbin portion 13b As shown in FIG. 5, the inner bobbin part 13a returns to the original state due to its flexibility.
a, the outer bobbin portion 13b is in close contact with the coil outer diameter 2b.

The state in which the inner bobbin portion 13a and the outer bobbin portion 13b are in close contact with the air core coil 2 in this way is the original state of this molded product. ld is reproduced,
The integrated diaphragm 1 with the air core coil 2 attached thereto (hereinafter referred to as a coiled diaphragm 1C) can be easily removed from the diaphragm receiving jig 3.

The air-core coil 2 arranged as described above
Is in close contact with the inner bobbin portion 13a and the outer bobbin portion 13b, but is in a sandwiched state and lacks strength at the time of input. Therefore, as shown in FIG. , And the air core coil 2 and the inner bobbin portion 13a and the outer bobbin portion 13b are bonded and fixed. In the embodiment, the adhesive h is a UV anaerobic type adhesive h.
When a predetermined amount is applied and then left for a predetermined time (several minutes), the adhesive h is caused by a capillary phenomenon or the like between the coil wires or between the air core coil 2 and the inner bobbin portion 13a and the outer bobbin portion 13.
The adhesive h penetrates into the minute gaps of b, so that the so-called adhesive h becomes familiar.

In this state, when the portion to which the adhesive h is applied is irradiated with an ultraviolet irradiator, the irradiated portion (the surface portion of the adhesive h filled in the gap L) is first hardened, and the portion to which the ultraviolet light does not reach, Since the surface portion of the adhesive h has already been cured and the air has been shut off, it is anaerobically cured. When the adhesive h is cured, the air-core coil 2 is moved to the inner bobbin portion 13a.
And, it is securely bonded to the outer bobbin portion 13b, and is sealed in the U-shaped groove to be in an extremely stable state.

In the second embodiment, the integrated diaphragm 1 is formed from a PPTA film using the molding die used in the first embodiment, and the method of mounting the air-core coil 2 is the same as in the first embodiment. did. As a result, the outer bobbin portion 13b is deformed and molded due to the shrinkage and the like of the PPTA film in the same manner as the molding of the integral diaphragm 1 using the conventional PPTA film described above. As shown in FIG. 7, the inner bobbin portion 13a and the outer bobbin portion 13b
Of the diaphragm receiving jig 3
Since the air-core coil 2 is adsorbed on the wall 1, there is no effect when the air-core coil 2 is inserted, and there is no possibility that the insertion is difficult or impossible as in the related art, and the air-core coil 2 is easily mounted. In addition to the above, it is possible to find an advantage that the deformed portion of the outer bobbin portion 13b exhibits stronger flexibility than the normal non-deformed outer bobbin portion 13b, and the springback force is increased, so that the degree of adhesion is improved. Was completed.

Further, looking at the cross sections of the inner bobbin portion 13a and the outer bobbin portion 13b after the air-core coil 2 is mounted, as shown in FIG. 8, the ordinary integral diaphragm 1, for example, made of a PI film, does not deform. The opening of the U-shaped groove is narrower than the integrated diaphragm 1 having the inner bobbin portion 13a and the outer bobbin portion 13b. Therefore, when the adhesive is applied to the gap L as in the case of the integral diaphragm made of a PI film, the cross-sectional area becomes smaller as the gap becomes smaller, so that the amount of the adhesive to be applied can be reduced and the integral diaphragm 1 can be used. Weight becomes lighter.

In a subsequent experiment, when molding a PI film other than a PPTA film, the inner bobbin portion 13a and the outer bobbin portion are controlled by controlling the molding conditions and the demolding method in accordance with the characteristics of the film. It has been found that it is possible to deform and mold 13b, and that it can be applied as a method of mounting the air-core coil 2 to most of the integral diaphragm 1. In the local enlarged views of FIGS. 2 to 5 and FIG.
Displaying the correlation position of is omitted because the figure is complicated and difficult to understand.

[0034]

According to the method of mounting the voice coil of the present invention, the inner bobbin portion and the outer bobbin portion are formed in a substantially U-shaped cross section, particularly the U-shaped bobbin formed on the integral diaphragm. It is extremely easy to mount the air-core coil in the groove, and it is possible to mount the air-core coil in close contact without providing an unnecessary large clearance between the inner bobbin and the outer bobbin and the air-core coil.

Further, the voice coil mounting apparatus can be easily implemented simply by improving a conventional apparatus comprising a diaphragm receiving jig and a coil jig.

The voice coil structure obtained by the voice coil mounting method of the present invention has an effective coil thickness because there is no unnecessarily large clearance between the inner bobbin and the outer bobbin and the air-core coil. Moreover, it is advantageous for weight reduction.

[Brief description of the drawings]

FIG. 1 is a partial sectional view showing an embodiment of a voice coil mounting device according to the present invention.

FIG. 2 is an enlarged partial cross-sectional view showing a state in which a bobbin of an integrated diaphragm is inserted into a groove of a diaphragm receiving jig.

FIG. 3 is an enlarged partial cross-sectional view showing a state in which a bobbin of an integrated diaphragm 1 is attracted to a peripheral wall surface of a groove of a diaphragm receiving jig.

FIG. 4 is an enlarged partial cross-sectional view showing a state in which an air core coil is inserted into a bobbin adsorbed on a peripheral wall surface of a groove of a diaphragm receiving jig.

FIG. 5 is a partially enlarged cross-sectional view showing a state in which a bobbin and an air core coil are in close contact with each other.

FIG. 6 is a cross-sectional view showing a voice coil structure in a completed state in which an adhesive is filled from an opening of a bobbin.

FIG. 7 is a partially enlarged cross-sectional view showing a state where a deformed portion is expanded even when an outer bobbin portion is deformed and molded.

FIG. 8 is an enlarged partial cross-sectional view showing a state in which an air core coil is mounted on a bobbin formed by deforming an outer bobbin portion and completed.

FIG. 9 is a sectional view showing the relationship between a conventional integrated diaphragm and an air-core coil.

FIG. 10 is a cross-sectional view of a relative arrangement of a conventional diaphragm receiving jig, a coil jig, and an integrated diaphragm.

FIG. 11 is an enlarged partial cross-sectional view showing a conventional bobbin in which an outer bobbin portion is deformed and molded.

FIG. 12 is a perspective view and a partially enlarged sectional view showing a general speaker voice coil structure.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Integrated diaphragm 11 Cone diaphragm 12 Chamber 13a Inner bobbin part 13b Outer bobbin part 2 Air core coil 3 Diaphragm receiving jig 31 Groove part 32 Suction hole 4 Coil jig h Adhesive

Continuation of front page (56) References JP-A-2-67100 (JP, A) JP-A-7-88853 (JP, A) JP-A-6-73999 (JP, U) (58) Fields surveyed (Int) .Cl. ⁷ , DB name) H04R 9/04 102 H04R 9/04 104 H04R 31/00

Claims (6)

(57) [Claims] 1. A bobbin of a voice coil is formed into a substantially U-shaped cross section by an inner bobbin portion and an outer bobbin portion by film forming, and a U-shaped groove formed by a U-shaped portion of both bobbin portions. In a voice coil structure in which an air-core coil is disposed and fixed by an adhesive, the U-shaped groove
Is smaller than the cross-sectional width of the air-core coil during film forming.
And can be wider than its cross-sectional width.
So that the inserted air core coil is sandwiched by elastic force.
The voice coil structure characterized by that. 2. The chamber according to claim 1, wherein the inner bobbin is a diaphragm.
And the outer bobbin is
2. The method according to claim 1, wherein the moving plate is formed integrally with the moving plate.
The described voice coil structure. 3. The voice coil bobbin is used for film forming.
Cross section of the inner bobbin and outer bobbin is approximately "U" shaped
And formed of a "U" -shaped portion of both bobbin portions.
Voice coil mounting the air core coil in the U-shaped groove
In the mounting method, the cross-section is approximately so that the bobbin is fitted.
Has a U-shaped groove and forms a suction hole in the groove
Insert the bobbin into the mold that has been
The inside bobbin portion and the
And the outer bobbin portion is attracted to the peripheral surface of the groove so that the air core
Form the clearance required to insert the
After inserting the core coil, the inside of the groove is returned to a positive pressure and
An inner bobbin portion, the outer bobbin portion, and the air core coil;
And fix the U-shaped groove by filling it with adhesive.
A method of mounting a voice coil, characterized in that: 4. The method according to claim 1, wherein the inner bobbin portion includes a chamber,
The outer bobbin is molded integrally with the cone diaphragm
The method for mounting a voice coil according to claim 3, wherein: 5. An inner bobbin portion and an outer portion formed by film forming.
A voice coil formed in a U-shaped cross section with the bobbin
For mounting an air-core coil in the U-shaped groove of the bobbin
In the voice coil mounting device, at least the bobby
Provided with a groove having a substantially U-shaped cross section so that the
Forming a suction hole in the mold to create a negative pressure in the groove
A voice coil mounting device characterized by the following. 6. The mold is integrally formed with a chamber.
Molded integrally with the inner bobbin and cone diaphragm
A molding surface is provided for the outer bobbin portions to be in close contact with each other.
6. The voice coil mounting device according to claim 5, wherein: