JP3546247B2 - Speaker diaphragm - Google Patents

Description

[0001]
[Industrial applications]
The present invention provides heat resistance, cold resistance, moisture resistance, weather resistance, light resistance, ozone resistance, chemical resistance, and flex crack resistance of a synthetic rubber obtained by copolymerization of epichlorohydrin and ethylene oxide. The present invention relates to a diaphragm suitable for a speaker for high-frequency radiation, in particular, having a ventilation blocking property and the above-mentioned physical properties by being attached to the surface of a base material by utilizing the method.
[0002]
[Prior art]
Conventionally, a dome-shaped diaphragm 11 for a direct radiation type loudspeaker for a speaker of a direct radiation type is integrally formed with an acoustic radiation portion 12 having a spherical shell shape and an edge portion 13 having a corrugation on the outer periphery thereof as shown in FIG. There is something. In any case, the acoustic radiating section 12 is impregnated with a synthetic resin for shape preservation on a base material of a cloth material such as cotton or silk so that the acoustic radiating section 12 is not deformed by vibration. In order to prevent the sound pressure from being short-circuited due to pinholes, the diaphragm 11 is generally used in which the surface is coated with a filler such as polyurethane or rubber-based latex. ing.
[0003]
[Problems to be solved by the invention]
Accordingly, in the case of a conventional speaker diaphragm 11 of this type, when a thermosetting phenol resin paint or the like is used as a shape-retaining material, the weight of the acoustic radiating portion 12 of the diaphragm 11 is not increased. When the number is reduced, air permeability remains due to pinholes due to the fiber structure of the base material after molding, which causes deterioration in sound reproduction efficiency due to air leakage. Furthermore, when coloring is performed by adding a dye or the like to the coating agent to color the base material, the entire diaphragm becomes heavy due to the weight of the coating agent, or the surface is roughened by the weave of the cloth material, and the coloring state is poor, There was a problem that color unevenness appeared on the appearance.
[0004]
Further, when a thermosetting material such as a phenolic resin is impregnated and molded by heating, there is a defect that the molten resin adheres to a heating mold and solidifies, so that it cannot be easily peeled off. Furthermore, when a rubber-based latex or the like is applied for sealing for the weave of the base cloth, the weight increases and the mass of the acoustic vibration system increases. There is a disadvantage of deterioration.
[0005]
Therefore, in the case of coloring, it is usual to apply a (metal) sputtering process after forming with a normal coating agent, but the above-mentioned processing method is too costly and the color of the finish is high. There is a problem that unevenness is likely to occur and that the weight still increases.
[0006]
In addition, especially in the environment where physical properties such as heat resistance, cold resistance, moisture resistance, weather resistance, light resistance, ozone resistance, chemical resistance, and flex crack resistance are required when used as a speaker for high sound radiation. There was a regret that was not always perfect.
[0007]
Therefore, the present invention solves these conventional problems and, in order to maintain the required properties, coats a base material with a synthetic rubber obtained by copolymerization of epichlorohydrin and ethylene oxide, especially high-radiation The present invention relates to diaphragms 1 and 1 'used for a speaker.
[0008]
[Means for Solving the Problems]
The structure of the present invention for achieving the object will be described with reference to FIGS. 1 to 10 corresponding to the examples. The diaphragms 1 and 1 'of the present invention are obtained by copolymerizing epichlorohydrin and ethylene oxide. Synthetic rubber is uniformly kneaded with a compounding agent for improving dispersibility, and is passed through a base material 1a mainly composed of a cloth body in a diluent 2a of a synthetic rubber paste liquid aged. A dipping step of adhering the diluted synthetic rubber paste liquid 2a, and then applying a slightly thicker synthetic rubber paste liquid 2b, followed by a drying step, followed by a convex male silicon mold 6a for general shaping; The material 1f temporarily molded at about 150 ° C. and 50 Kg / cm ² for 1 second by the concave female mold 6b is applied at about 180 ° C. and 200 kg by the regular upper male silicone mold 6c and lower female mold 6d. / cm ² at about 10 After obtaining the material 1g was between vulcanization molding, even about 180 ° C., the vibrating plate 1, 1 for use in a speaker, characterized in that re-pressurized for 4-5 seconds at 200Kg / cm ² '.
[0009]
[Action]
In the present invention, since the diaphragms 1 and 1 'having such a configuration are used, the heat resistance, cold resistance, and moisture resistance of the primitive epichlorohydrin, which is the raw material of the synthetic rubber paste liquids 2a and 2b coated on the base material, are provided. Depending on physical properties such as weather resistance, light resistance, ozone resistance, chemical resistance, flex crack resistance, etc., the internal fabric material, natural fiber woven fabric, synthetic resin fiber woven fabric, or non-woven fabric of those fibers 1a is protected, and excellent properties can be obtained as a diaphragm for a speaker used in various environments.
[0010]
That is, since a synthetic rubber film obtained by copolymerization of epichlorohydrin and ethylene oxide is uniformly adhered and coated on the substrate 1a and laminated, the pinholes of the product generated during the shape preservation of the substrate 1a are formed. Since the occurrence can be prevented and the sealing strength can be maintained, the base material 1a can be made thinner, the weight can be reduced, the acoustic radiation efficiency cannot be reduced, and the cloth of the base material 1a can be reduced. Since it does not depend on the weave, the diaphragms 1 and 1 'having good color development can be formed.
[0011]
【Example】
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
In FIG. 1, FIG. 1 shows a synthetic glue diluent 2a obtained by uniformly kneading a compounding agent for improving dispersibility into a synthetic rubber obtained by copolymerizing (pulverized) epichlorohydrin and ethylene oxide, followed by aging. The diluted synthetic rubber paste liquid 2a is adhered to both surfaces of the base 1a through a base 1a mainly made of a cloth body into a liquid tank 2c filled with the undercoat paste, and thereafter, for example, a heating wire or the like A dipping step is shown in which, after drying by a drying device 3a heated by the above method, the substrate is wound around a bobbin as a substrate 1b after dipping. When attaching the diluted synthetic rubber paste liquid 2a to both surfaces of the substrate 1a, this process is repeated for the front and back surfaces of the substrate 1a.
[0012]
FIG. 2 shows that the synthetic rubber paste liquid 2b having a slightly higher concentration than that of the dipping step is extruded from the extracting device 2d onto the base material 1b subjected to the dipping process while controlling the thickness of the synthetic rubber paste solution 2d with a squeezer 2e or the like. A process is shown in which the synthetic rubber paste liquid 2b is adhered, dried by a drying device 3b heated by, for example, a heating wire or the like, and then wound as a substrate 1c to which the synthetic rubber paste liquid 2b is adhered.
[0013]
The thickness of the synthetic rubber paste liquid 2b can be freely adjusted while being extruded while being controlled by a squeezer 2e or the like, and the balance of physical properties such as the weight, hardness, and rigidity of the diaphragms 1 and 1 'can be achieved. Can be easily maintained, whereby the balance between the rigidity of the diaphragm and the internal loss can be changed. The process of FIG. 2 is repeated on the front and back surfaces of the base material 1c to which the synthetic rubber paste liquid 2b is attached as necessary.
[0014]
Next, at that time, after passing through a drying step, the polyethylene film 4 is inserted between the winding layers and overlapped, and a 28-cm band-like cloth with the polyethylene film 4 attached as a drawing cloth wound in a width of 90 cm × length 50 m. And wound on a bobbin as a substrate 1d (not shown).
[0015]
After the strip-shaped substrate 1d with a drawing cloth is punched into a substantially hexagonal temporary outer shape by a punching device 5a having a longitudinal section shown in FIG. 3A, the drawing of the polyethylene film 4 is removed, and the base material 1e is obtained. The step of forming is shown. FIG. 3B is a diagram showing a cross-sectional shape of a die of the punching device 5a.
[0016]
The base material 1e obtained in the preceding step is formed by a convex male silicon mold 6a for general shaping attached to a hot platen 7a having a sectional shape shown in FIG. 4 and a concave female mold 6b attached to a similar hot platen 7b. The step of temporarily forming a substrate 1f at 150 ° C. and 50 kg / cm ² for 1 second is shown.
[0017]
By preliminarily forming in this way, the constituent fibers of the base material 1a can be subjected to preliminary shape-retaining treatment, and the formation of wrinkles in the base material 1e due to rapid elongation can be prevented by the temporary forming. In the vulcanization step, the acoustic radiating part and corrugation edge part of the central part are molded and faithfully conformed to the shape of the mold by heating and pressing by the molding and pressing mold, and the shape can be firmly and reliably maintained. The outer shape can be easily processed and can be easily separated from the mold.
[0018]
The substantially hexagonal material 1f that has undergone the above-described temporary forming process is 180 ° C., 200 Kg, one sheet at a time, using upper and lower male and female molds 6c and 6d each having a regular shape whose cross-sectional shape is shown in FIG. / Cm ² , a step of vulcanizing for 10 minutes to form a substrate of 1 g.
[0019]
Further, 1 g of the base material is re-pressed at approximately 180 ° C. and 200 kg / cm ² for 4 to 5 seconds by the upper male silicone mold 6c and the lower female mold 6d having the regular shapes shown in FIG. 3 shows a pressure step. In this step, the vibrating plate 1b vulcanized in the vulcanizing step is removed from the pressing dies 6c and 6d and pressurized again, thereby shaping irregularities as the vibrating plate base 1h, improving mold release, and removing gas. This is the step of discharging.
[0020]
The diaphragm base 1h after the re-pressing is set in the punching device 5b, and the outer shape is punched and shaped by a die of a punching die 5b whose cross section is shown in FIG. FIG. 6B is a diagram showing a cross-sectional shape of a die of the punching device 5b.
[0021]
FIG. 7 is a partial cross-sectional outline view of a diaphragm 11 in which a corrugation edge 13 is integrally formed on the outer periphery of an acoustic radiating section 12, FIG. 8 is a partially enlarged cross-sectional view of the diaphragms 1 and 1 'of the present invention, and FIG. FIG. 2 is a sectional end view showing an arrangement relationship between the diaphragms 1 and 1 'of the present invention and other components. The outer circumferences of the diaphragms 1 and 1' are pasted and adhered on a magnetic circuit 20, and a voice coil bobbin 18 is further attached. The vibrating system is formed by bonding and attaching the voice coil 19 so that the voice coil 19 is loosely inserted into the magnetic gap 21 of the magnetic circuit 20.
[0022]
In FIG. 1, a base material 1a obtained by plain weaving, for example, a 70-denier polyester fiber and being heated and drawn out from a bobbin is used. As the material of the base material 1a, a woven fabric of polyester fibers is optimal, but a cotton cloth is used. , Lone silk, or other synthetic resin fibers may be used.
[0023]
The present invention is also applicable to a case in which only a central spherical shell-shaped acoustic radiation portion is formed, and a peripheral edge of a diaphragm having a separate corrugation is attached to the outer periphery thereof.
[0024]
Although the embodiments that are considered to be representative of the present invention have been described above, the present invention is not necessarily limited to only the structures of the embodiments, but includes the above-described constituent features of the present invention, and The above-mentioned object can be achieved, and can be carried out with appropriate modifications within a range having the following effects.
[0025]
【The invention's effect】
As is clear from the above description, the configuration of the diaphragm of the present invention is such that the base material 1 of cotton, silk, etc. is made of polyester, cotton cloth, or lone silk as a main material, epichlorohydrin is used as a raw material, and a compounding chemical is added thereto. A vulcanized configuration in which a layer of synthetic rubber paste aged and kneaded and aged, and then vulcanized makes it possible to make the base material 1 thinner accordingly, and the weight of the diaphragm 1 can be reduced. And the heat resistance, cold resistance, moisture resistance, weather resistance, light resistance, ozone resistance, chemical resistance, flex crack resistance, etc. of the synthetic rubber obtained by copolymerization of epichlorohydrin and ethylene oxide. Utilizing it and adhering it to the surface of the base material has the remarkable effect of having the air-permeability and the physical properties described above.
[0026]
The Young's modulus as a physical property of the material of the diaphragm of the present invention is 7.5 × 10 ⁹ dynes / cm ² ,
FIG. 10 shows a sound pressure frequency characteristic table of a speaker using the diaphragm of the present invention, in which the horizontal axis represents frequency and the vertical axis represents sound pressure. The characteristics indicated by the thick lines are for the speaker using the diaphragm of the present invention. In this sound pressure frequency characteristic table, the speaker using the diaphragm of the present invention shows 2-3 dB higher sound pressure sensitivity in a high frequency band of 7 to 20 KHz compared to the conventional example, which is a good result as a high sound speaker. Is shown. Also, the sound quality is clear and soft.
[Brief description of the drawings]
FIG. 1 is a process chart showing a dipping step.
FIG. 2 shows a synthetic rubber paste liquid 2b having a slightly higher concentration than that of the dipping step and is extruded from the extracting device 2d onto the base material 1b after the dipping process while controlling the thickness of the synthetic rubber paste liquid with a squeezer 2e or the like. FIG. 4 is a process diagram showing a process of applying a liquid 2b, drying the dried product by a drying device 3b, attaching a rubber paste liquid, and winding the substrate as a substrate 1c.
FIG. 3A is a process diagram showing a process of punching a base material 1d (pulled cloth 1d) cut into a strip into a temporary hexagonal outer shape by a punching device 5a to form a base material 1e.
FIG. 3B is a diagram showing a cross-sectional shape of a die of the punching device 5a.
FIG. 4 is a cross-sectional view of a convex male silicon mold 6a and a concave female mold 6b for general shaping.
FIG. 5 is a cross-sectional view of an upper male silicon mold 6c and a lower female mold 6d of a regular shape.
FIG. 6A is a longitudinal sectional view of a die of a punching device 5b.
FIG. 6B
FIG. 6A is a diagram showing a cross-sectional shape of a die of a punching device 5b of FIG.
FIG. 7 is a half sectional external view of a formed diaphragm.
FIG. 8 is a partially enlarged sectional view of the diaphragm of the present invention.
FIG. 9 is a partial view showing a diaphragm edge and an end face of a cut surface in an arrangement relationship thereof.
FIG. 10 shows a sound pressure frequency characteristic table of a speaker using the diaphragm of the present invention.
[Explanation of symbols]
1a Base material 1f Temporarily formed base material 2a Rubber diluent liquid diluent 2b Slightly thick rubber paste liquid 6a Convex male silicone mold 6b for general shaping Concave female mold 6c for general shaping Above regular shape Male silicon mold 6d Regular female lower mold female gold

Claims (2)

The cloth is used as a base material in a diluent 2a of a synthetic rubber paste liquid obtained by mixing kneading chemicals for improving dispersibility into a synthetic rubber obtained by copolymerizing epichlorohydrin with ethylene oxide, and then aged. After passing through the base material 1a, a dipping step of attaching the diluted synthetic rubber paste liquid 2a to both surfaces of the base material 1a, and then applying a slightly thicker synthetic rubber paste liquid 2b, followed by a drying step The material 1f obtained by temporarily forming the convex male silicon mold 6a for rough shaping and the concave female mold 6b at 50 ° C./cm ² at about 150 ° C. for 1 second is formed into a regular upper mold. After vulcanization molding at about 180 ° C. and 200 kg / cm ² for 10 minutes using the silicon mold 6 c and the lower female mold 6 d, it was further repressurized at about 180 ° C. and 200 kg / cm ² for 4 to 5 seconds. Features Speaker diaphragm 1. 2. The speaker diaphragm 1 ′ according to claim 1, wherein the base body of the base material 1 is one of a natural fiber woven fabric, a synthetic resin fiber woven fabric, and a nonwoven fabric of these fibers.

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