JPH1013996A - Loudspeaker and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inexpensive loudspeaker with superior heat resistance by using inorganic material with high cost performance in material and manufacturing, for a voice coil and a diaphragm. SOLUTION: The voice coil is manufactured by using inorganic high polymer resin, sintered as a cylindrical body consisting essentially of silicone resin and synthetic mica as a bobbin, winding a wire coated with the same resin round the bobbin and forming a layer of the same resin in a surface of the coil. In addition, a paper pulp-based material 11 is sintered by radially providing plural slits 12 on it at appropriate intervals and applying the inorganic high polymer resin in both surface of the paper pulp-based material 11. A layer of the inorganic high polymer resin on both surfaces of the paper pulp base material is connected by a bringing part of the inorganic high polymer resin, filled in the plural slits 12.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a loudspeaker used for audio equipment and the like and a method of manufacturing the loudspeaker, and more particularly to an improvement for improving heat resistance of a voice coil and a diaphragm.

[0002]

2. Description of the Related Art In recent years, with the digitization of reproduced music sources in the audio-related industry, there has been a demand for loudspeakers as sound output devices to have higher sound quality and higher output than before.

[0003] Since the operating temperature of a voice coil of a speaker, especially in a high-output speaker, reaches several hundred degrees, the insulating film coated on the copper wire of the voice coil is deteriorated by heat, and a short circuit between the copper wires occurs. May be. At such a high temperature, the adhesive fixing the wire of the voice coil and the bobbin is degraded, and the coil may be disassembled and may be broken.

As a wire material for a voice coil of a speaker, a copper wire which is insulated and coated with an organic material such as varnish is often used, but such a wire material has a low heat-resistant temperature. Further, the same organic material is often used for the adhesive between the bobbin and the coil, but the heat resistance temperature still becomes a problem. In a speaker that requires a large output, such as a monitor speaker, the heat generated inside deteriorates the insulating material of the coil wire and the organic material used as an adhesive with the bobbin, causing short-circuit between wires and looseness of the coil. Inconvenience such as injury is likely to occur. This limits the performance of the loudspeaker and limits the performance of the loudspeaker even when using a composite material diaphragm or rubber edge that is more durable than a paper pulp diaphragm or cloth edge, or using a neodymium magnet with a high magnetic flux density. At present, it cannot be demonstrated.

[0005] In order to improve the heat resistance of the voice coil, a polyimide film or aluminum having good heat conductivity is generally used as a material of the bobbin. It deteriorates and cannot maintain its initial shape and physical properties. In the short term, when the temperature approaches 400 ° C., the polyimide film is carbonized, and aluminum is deformed.

Some diaphragms of loudspeakers are made of ceramics or metal in order to improve heat resistance and rigidity. However, the specific gravity of each material is high, and the sound pressure is reduced as the weight of the diaphragm is increased, so that the applications are limited. In addition, when any of the materials is used, the material cost and the manufacturing cost are expensive.
Since a characteristic problem arises in that a sound quality specific to the inorganic material is added, the speaker cannot be used as a general-purpose speaker.

Other diaphragm materials include those obtained by applying a ceramic slurry to a paper substrate and then sintering, and those obtained by directly spraying ceramic onto a paper pulp diaphragm to impart rigidity. However, in an environment of a high temperature (about 300 to 400 ° C.) in which the paper pulp burns or carbonizes, the ceramic layer is warped or peeled off. Therefore, from the viewpoint of heat resistance in such a high temperature environment, it is practical. Not a target. When the ceramic layer is warped, the symmetry of the vibration may be lost and the ceramic layer may be broken. If the ceramic layer is peeled off, the pulp is likely to burn. Therefore, for a large-diameter speaker having a large flammable area, it is not preferable from the viewpoint of safety that a diaphragm simply coated with ceramics on paper pulp is used.

On the other hand, if the ceramic layer is made to have a thickness that maintains rigidity so that warpage or peeling does not occur at a high temperature, the sound pressure is reduced due to an increase in the weight of the diaphragm, the material cost is increased, and the physical properties of the ceramic are reduced. This causes problems such as a change in sound quality.

[0009]

As described above, in the conventional loudspeaker, the material of the film of the voice coil, the adhesive between the wire and the bobbin, and the material of the diaphragm are designed to achieve high output and high performance. It is a hindrance factor.

Accordingly, an object of the present invention is to provide a speaker which is inexpensive and has excellent heat resistance by using an inorganic material having excellent cost performance in terms of materials and manufacturing for a voice coil and a diaphragm.

[0011]

In order to achieve this object, a loudspeaker according to the present invention has a voice formed by sintering an inorganic polymer resin containing silicone resin and synthetic mica as main components as a cylindrical molded body. Used as a bobbin for coil.
Thereby, the heat resistance of the voice coil is improved.

As a specific method of manufacturing the bobbin for the voice coil, preferably, the side surface of the cylindrical jig is coated with a combustible polymer resin so as to have a substantially uniform film thickness, and the surface thereof is further coated with a silicone resin and After coating the inorganic polymer resin whose main component is synthetic mica so as to have a substantially uniform coating thickness, and sintering the jig together with the specified temperature,
By heating at a temperature at which the flammable polymer resin is decomposed, the layer of the flammable polymer resin disappears, and thereafter,
The cylindrical bobbin made of the inorganic polymer resin layer is removed from the jig. The disappearance of the combustible polymer resin layer creates a gap between the jig and the bobbin, making it easier to remove the bobbin from the jig. In this way, it is possible to mass-produce an inorganic heat-resistant bobbin that is seamless and continuous.

Instead of forming a flammable polymer resin film on the jig, paper pulp having a substantially uniform thickness may be attached to the jig using a flammable adhesive. In this case, it is preferable to provide a plurality of cuts in the axial direction of the paper pulp adhered in a cylindrical shape. Since the strain due to the heat shrinkage of the paper pulp is dispersed in the plurality of cuts, cracks in the resin film formed thereon are suppressed.

The cylindrical jig used in the above-described method of manufacturing a bobbin for a voice coil is preferably made of a ceramic material having a small coefficient of thermal expansion.

As a method of manufacturing a voice coil using the inorganic heat-resistant bobbin manufactured as described above, a wire coated with an inorganic polymer resin containing silicone resin and synthetic mica as a main component is also used. It is preferable to form a coil by winding it around a bobbin, coat the surface of the coil with the inorganic polymer resin, and then sinter to fix the bobbin and the wire. The voice coil manufactured in this manner is unlikely to cause problems such as deterioration of the film of the wire and short-circuiting or the wire is scattered even at a high temperature, and is excellent in heat resistance.

Another feature of the speaker of the present invention is that a paper pulp base material is impregnated with an inorganic polymer resin containing silicone resin and synthetic mica as a main component and then sintered to form an inorganic film. That is, a paper base diaphragm is used.

Preferably, a plurality of slits are provided at appropriate intervals in the paper pulp substrate, and the inorganic polymer resin is applied to both surfaces of the paper pulp substrate and sintered. According to this method, the inorganic polymer resin layer is formed on both surfaces of the paper pulp substrate, and the paper pulp substrate is formed by a cross-linking portion of the inorganic polymer resin filled in the plurality of slits. Are connected to each other. As a result, the rigidity of the inorganic polymer resin layer is increased, and peeling of the inorganic polymer resin layer from the paper pulp base material is less likely to occur.

The inorganic polymer resin used for any of the voice coil bobbin, wire coating and diaphragm is mainly composed of a mixture of silicone resin and synthetic mica at a ratio of 1: 1. Is preferred.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the method for manufacturing a speaker according to the present invention will be described below in the order of manufacturing a bobbin for a voice coil, manufacturing a voice coil, and manufacturing a diaphragm.

First, a first method for manufacturing a bobbin for a voice coil will be described with reference to FIGS. A columnar jig B as shown in FIG. 1 is prepared. As a material for the jig, an inorganic material having a low coefficient of thermal expansion at a high temperature, such as ceramic, is desirable. Acrylic resin 1 is dip-coated on the surface of this cylindrical jig B, as shown in FIG. On this occasion,
The concentration of the solution and the pulling speed are adjusted so that the film thickness of the resin becomes about 100 microns. Instead of acrylic resin, epoxy resin, melamine resin, urethane resin,
A urea resin or the like may be used. In essence, any flammable polymer resin may be used, and the lower the combustion decomposition temperature, the better.

After that, it is dried and cured in a thermostat at about 80 ° C. for about 1 hour. Next, on the acrylic resin film 1, an inorganic polymer resin whose main component is a mixture of a silicone resin and synthetic mica at a ratio of about 1: 1 is dip coated. Also in this case, the thickness of the solution is adjusted to about 100 microns by adjusting the concentration of the solution and the pulling speed. Also, as shown in FIG. 3, the mask tapes 2a and 2a are wrapped around the upper and lower ends of the acrylic resin film.
2b is pasted in advance. Therefore, the inorganic polymer resin 3 is dip-coated on the acrylic resin film 1 between the upper and lower mask tapes 2a and 2b.

The columnar jig B thus formed with the two-layer coating is dried and hardened in a thermostat at about 80 ° C., and further cured in a thermostat at about 200 ° C. for about 1 hour. Sinter. Next, it is heated in an electric furnace at about 400 ° C. for about one hour to burn and decompose the acrylic resin. After cooling, the remaining inorganic polymer resin layer 3 is removed from the jig B. Since a gap corresponding to the disappeared acrylic resin of 100 μm is formed between the inorganic polymer resin layer 3 and the jig B, the inorganic polymer resin layer 3 can be easily removed from the jig B.

In this manner, a cylindrical bobbin for a voice coil as shown in FIG. 4 comprising the inorganic polymer resin layer is obtained. This bobbin is a cylindrical molded body having no breaks or seams and having continuity. When thermal expansion occurs, the bobbin expands uniformly in the circumferential direction, so that the center of gravity does not move due to deformation. Therefore, the vertical movement at the time of driving the voice coil can be kept stable. In addition, unlike the conventional bobbin having a discontinuity, local distortion around the discontinuity does not occur. Therefore, even in operation at high temperatures, adverse effects on the adhesive and the voice coil film are reduced.

Paper pulp may be used in place of the acrylic resin (or other flammable polymer resin) used in the first method of manufacturing the voice coil bobbin. That is, in the second method of manufacturing a bobbin for a voice coil, as shown in FIG. 5, a paper pulp 4 having a uniform thickness of about 100 microns is wound around a cylindrical jig B and glued. 8 directions
A cut 5 is made in the paper pulp 4 so as to be equally divided. What has been cut into strips in advance may be glued around the jig B.

The cut 5 has a function of reducing the influence on the resin film formed thereon when the paper pulp shrinks at a high temperature. In other words, if there is no break,
The paper pulp shrinks due to heat and eventually cracks occur in the paper pulp.At this time, the strain of the resin film formed on the paper pulp concentrates on the cracked part, and the resin film eventually cracks I will. On the other hand, if a plurality of cuts are provided in advance, the distortion due to the heat shrinkage of the paper pulp is dispersed at the plurality of cuts, thereby suppressing cracking of the resin.

The subsequent steps are the same as in the first manufacturing method.
After masking the upper and lower ends of the paper pulp, an inorganic polymer resin containing silicone resin and synthetic mica as main components is dip-coated on the paper pulp (FIG. 3). Then, the paper pulp 4 is burned and decomposed in a 400 ° C. electric furnace after being dried and hardened in an 80 ° C. constant temperature bath and sintered in a 200 ° C. constant temperature bath. After cooling, the inorganic polymer resin layer 3 is removed from the jig B, and a cylindrical bobbin as shown in FIG. 4 is obtained.

Next, a method of manufacturing the voice coil will be described with reference to FIGS. The bobbin 3 produced by the above-described method is set on the winding machine 6 of the equipment as shown in FIG.
The equipment shown in FIG. 6 is for continuously performing from the resin coating of the wire 7 to the winding. An unprocessed wire (copper wire) 7 is sent out from a reel 8 and is coated with a resin by passing through a dip tank 9. The dip tank 9 contains an inorganic polymer resin solution whose main component is a mixture of a silicone resin and synthetic mica in a ratio of about 1: 1. The concentration of the solution is adjusted so that the film thickness of the resin coated on the wire becomes about 10 microns. Preferably, a copper wire having a diameter of about 300 microns is used for the wire.

Thereafter, the wire passes through a heating and drying tube 10 adjusted to about 200 ° C. in order to dry the resin film. In this way, the wire on which the coating of the inorganic polymer resin containing the silicone resin and the synthetic mica as main components is formed is supplied to the winding machine 6 and wound around the bobbin 3.

A bobbin (voice coil) whose winding is completed
Is removed from the winding machine 6, and an inorganic polymer resin containing silicone resin and synthetic mica as main components is sprayed so as to cover the entire surface of the winding with a film having a thickness of about 100 microns. Thereafter, the voice coil is left in a constant temperature bath at 80 ° C. for about 1 hour, and sintering is further performed at about 200 ° C. for about 1 hour. A test was conducted in which the thus obtained voice coil as shown in FIG. 7 was left in an electric furnace at about 700 ° C. for about 1 hour, and no abnormalities such as cracks and deformation were found. When the operation test of the speaker was performed using the voice coil, the speaker operated normally.

In the above-described voice coil manufacturing method, the steps from the resin coating of the wire to the winding are performed continuously. However, in some cases, the resin coating of the wire and the winding may be separately batch-processed. In this case, after the wire is coated with a resin and dried, the wire is wound by a winding machine similar to the reel 8 instead of being supplied to the winding machine. When winding, the coated wire is directly supplied from the winding machine to the winding machine. The film thickness of the resin to be coated on the wire can be adjusted not only by the concentration of the resin solution but also by the moving speed of the wire. Further, by performing the resin coating in a plurality of times (for example, three times), it is possible to improve the quality of the film and prevent the peeling of the film due to bending and the occurrence of pinholes.

However, in the series of equipment from the resin coating to the winding shown in FIG. 6, a plurality of sets of the dip tank 9 and the heating / drying tube 10 are connected in series to perform the resin coating in a plurality of times. You may.

Next, a method of manufacturing the diaphragm will be described with reference to FIGS. First, a diaphragm substrate 11 made of paper pulp
Next, radial slits 12 as shown in FIG. 8 are provided at a plurality of locations at appropriate intervals. Next, an inorganic polymer resin 13 containing, as a main component, a mixture of silicone resin and synthetic mica in a ratio of 1: 1 is applied to both surfaces of the diaphragm base material 11. Then, after drying in a thermostat at about 80 ° C. for about 1 hour, sintering is performed at about 200 ° C. for about 1 hour.

FIG. 9 shows a cross section of the diaphragm thus obtained. This corresponds to the section 9A-9B in FIG. A state in which the inorganic polymer resin layers 13 applied to both surfaces of the paper pulp base material 11 are connected by the inorganic polymer resin cross-linking portions 13a filled in the slits 12 provided in the paper pulp base material. It is shown. As a result, the rigidity of the inorganic polymer resin layer 13 increases, and peeling of the inorganic polymer resin layer 13 from the pulp base material 11 hardly occurs. In a heating experiment using a gas burner, the inorganic polymer resin layer 13 did not warp even when the paper pulp substrate was burned out.

[0034]

As described above, according to the present invention, a wire having the same resin film formed thereon is wound on a bobbin formed of an inorganic polymer resin containing silicone resin and synthetic mica as main components, and a coil is formed. By using a voice coil obtained by further forming a film of the same resin on the surface, it is possible to realize a speaker having excellent heat resistance, in which short-circuiting and loosening of the winding are less likely to occur even at a high temperature.

Also, the heat resistance of the diaphragm can be improved by using a paper pulp base material impregnated with an inorganic polymer resin containing silicone resin and synthetic mica as a main component and then sintered. it can. Furthermore, the paper pulp base material is provided with a plurality of slits, and the resin film formed on both sides of the base material is connected by the cross-linking portion of the resin filled in this portion, so that the resin layer and the base material are separated from each other. Less likely to occur.

[Brief description of the drawings]

FIG. 1 is an external view of a ceramic cylindrical jig used in a process of manufacturing a voice coil bobbin of a speaker according to an embodiment of the present invention.

FIG. 2 is an external view showing one process in manufacturing a bobbin for a voice coil.

FIG. 3 is an external view showing another process in the production of the bobbin for the voice coil.

FIG. 4 is an external view of a bobbin for a voice coil manufactured by the method of the present invention.

FIG. 5 is an external view showing one step in another method of manufacturing the bobbin for the voice coil.

FIG. 6 is a schematic diagram of a series of manufacturing equipment from coating of a wire for a voice coil of a speaker to winding according to the present invention.

FIG. 7 is an external view of a speaker voice coil manufactured by the method of the present invention.

FIG. 8 is an external view of a paper base material used for a diaphragm of the speaker according to the embodiment of the present invention.

FIG. 9 is a cross-sectional view of 9A-9B after the resin coating is applied to both sides of the paper base material of FIG. 8 and sintered.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Acrylic resin 2a, 2b Mask tape 3 Inorganic polymer resin 4 Paper pulp 5 Cut 6 Winding machine 7 Wire before resin coating 8 Wire reel 9 Dip tank 10 Heat drying tube 11 Paper pulp base material 12 Slit 13 Inorganic system Polymer resin layer 13a Cross-linked part

Claims (10)

[Claims] The present invention relates to a bobbin for a voice coil, which is obtained by sintering an inorganic polymer resin containing silicone resin and synthetic mica as a main component as a cylindrical molded body.
A speaker having improved heat resistance of a voice coil. 2. A side surface of a cylindrical jig is coated with a flammable polymer resin so as to have a substantially uniform film thickness, and the surface thereof is further coated with an inorganic polymer resin containing silicone resin and synthetic mica as main components. Is coated so as to have a substantially uniform coating thickness, and the jig is sintered at a predetermined temperature, and then heated at a temperature at which the flammable polymer resin is decomposed, whereby the flammable polymer resin layer is heated. Removing the cylindrical bobbin made of the inorganic polymer resin layer from the jig, and thereafter removing the cylindrical bobbin from the jig. 3. A paper pulp having a substantially uniform thickness and a plurality of cuts in an axial direction is attached to the side surface of a cylindrical jig using a combustible adhesive, and a silicone resin and a synthetic resin are applied to the surface thereof. An inorganic polymer resin containing mica as a main component is coated so as to have a substantially uniform film thickness, and the jig is sintered at a predetermined temperature, and then heated at a temperature at which the paper pulp is carbonized. A method for manufacturing a bobbin for a voice coil, comprising: removing a paper pulp layer; and removing a cylindrical bobbin made of the inorganic polymer resin layer from the jig. 4. A cylindrical jig made of a ceramic material having a small coefficient of thermal expansion is used as said jig.
Or the method of manufacturing the bobbin for a voice coil according to 3. 5. A bobbin obtained by sintering an inorganic polymer resin containing silicone resin and synthetic mica as main components as a cylindrical molded body, and winding a wire coated with the inorganic polymer resin on a bobbin. A method of manufacturing a voice coil, comprising: forming a coil; coating the surface of the coil with the inorganic polymer resin; and sintering to fix the bobbin and the wire. 6. A paper base diaphragm in which an inorganic coating is formed by impregnating a paper pulp base material with an inorganic polymer resin containing a silicone resin and a synthetic mica as main components and sintering the paper pulp base material. Features speaker. 7. The paper pulp base material is provided by providing a plurality of slits in the paper pulp base material at appropriate intervals and applying and sintering the inorganic polymer resin on both surfaces of the paper pulp base material. The inorganic polymer resin layers are formed on both sides of the paper pulp substrate, and the inorganic polymer resin layers on both surfaces of the paper pulp substrate are formed by the cross-linking portions of the inorganic polymer resin filled in the plurality of slits. The speaker according to claim 6, which is connected. 8. The loudspeaker according to claim 1, wherein the inorganic polymer resin is mainly composed of a mixture of silicone resin and synthetic mica at a ratio of 1: 1. 9. The method for producing a bobbin for a voice coil according to claim 2, wherein the inorganic polymer resin is mainly composed of a mixture of a silicone resin and a synthetic mica at a ratio of 1: 1. . 10. The method of manufacturing a voice coil according to claim 5, wherein the inorganic polymer resin is mainly composed of a mixture of a silicone resin and a synthetic mica at a ratio of 1: 1.