JP2006287830A - Method of manufacturing diaphragm for electro-acoustic transducer and diaphragm for electro-acoustic transducer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing a diaphragm for electro-acoustic transducer with which overflow or short-circuit is prevented when filling clearance of a mold with photo-setting resins, air bubbles are also prevented from being held in and a diaphragm for electro-acoustic transducer can be easily and inexpensively manufactured with a little man-hour, and a diaphragm for electro-acoustic transducer manufactured therewith. <P>SOLUTION: Upper and lower dies are clamped and the clearance of a mold thereof is filled with photo-setting resins from the outside through a gate. Thus, overflow or short-circuit of the photo-setting resins, holding of air bubbles in filling the clearance with resins, etc., are prevented. At least one of the upper and lower dies is comprised of a light transmissible material, and the photo-setting resins are cured by irradiating them with ultraviolet rays or visible light beams from the outside, thereby manufacturing the diaphragm. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a diaphragm for an electroacoustic transducer such as a speaker or a microphone, which is a kind of acoustic equipment, and a diaphragm for an electroacoustic transducer.

  Conventionally, for example, as disclosed in Japanese Patent Application Laid-Open No. 2001-204094, a diaphragm for a micro speaker and a diaphragm for a dome speaker are mainly composed of a film, a woven fabric coated with rubber, etc., a planar material such as an elastomer, or the like. Often used in combination.

  Examples of film materials include PET: polyethylene terephthalate, PEI: polyetherimide, PC: polycarbonate, PEN: polyethylene naphthalate, PI: polyimide.

  In addition, as an example of a woven fabric coated with rubber or the like, a base material is a cellulose fiber woven fabric, a chemical fiber woven fabric such as polyester, or the like, and a rubber coat such as SBR or NBR is present.

  Examples of elastomers include olefin-based, urethane-based, and EPDM-based elastomers.

Further, as the molding method, there are vacuum molding, pressure molding, heating and pressure molding using a molding die (hereinafter referred to as an upper and lower die), which is a set of an upper die and a lower die, and an injection molding method.
JP2001-204094

  In vacuum forming, pressure forming, heating and pressure forming using upper and lower molds, etc., it is necessary to raise the mold temperature to near the melting point of the material, and enormous energy is required for heating. Further, since it is necessary to cool and remove the mold, a long time is spent in the molding cycle.

  In the injection molding method, the melted resin is cooled immediately after coming into contact with a mold having a temperature difference, and the fluidity is extremely reduced. Therefore, it is difficult to obtain a thin diaphragm, and heating, injection, holding pressure, etc. This makes the equipment expensive. Further, since the thermoplastic material is heated to near the melting point, the heating energy is enormous.

  The material used for molding is vacuum forming, pressure forming, heating and pressure forming with upper and lower molds, etc., after molding a planar material that is substantially larger than the part dimensions, the part part is cut out and used. This is also not preferable. In addition, the price of parts will increase.

  Since the above-described constituent materials for vacuum forming, pressure forming, and heat forming by upper and lower molds are generally uniform thickness materials, the respective portions have substantially the same thickness after forming. The thickness (ie, rigidity) of each part of the diaphragm cannot be changed from a uniform thickness material. A method of changing the thickness by changing the clearance of the mold or performing a process such as stretching at the time of molding as shown in Japanese Patent No. 338498 has been proposed, but the internal stress distortion after molding is large, In addition, there is a drawback that the molding die is complicated.

  In addition, an edge, a gasket, or the like may be joined to the molded diaphragm with an adhesive, but the amount of adhesive applied varies, adhesive strength varies, etc., and the characteristics are not stable. In the case of a material having poor adhesion, it is necessary to perform a secondary treatment such as a primer. As described above, the fixing method using an adhesive has a problem in reliability, and requires an extra processing man-hour, leading to an increase in price.

  A planar material such as a film has a limited thickness that is manufactured industrially, and it is usually difficult to obtain a material with a thickness other than that.

  Also, planar materials such as films have limited physical properties of industrially manufactured materials, and obtaining materials containing reinforcing materials such as fillers are usually technical and economical. Is difficult.

  The present invention has been proposed in view of the above, and its object is to prevent overflow and short-circuit when filling the clearance of the mold with a photocurable resin, and to prevent entrapment of bubbles, An object of the present invention is to provide a method for manufacturing a diaphragm for an electroacoustic transducer that can be easily and inexpensively manufactured with a small number of man-hours, and a diaphragm for an electroacoustic transducer manufactured thereby.

According to the first aspect of the present invention, at least one of a set of molds including the upper mold and the lower mold is formed of a material that transmits ultraviolet rays and / or visible light, and the mold is closed. The inside of the mold is filled with a resin that cures by ultraviolet rays and / or visible light through a gate formed in the mold, and the resin is cured by irradiating ultraviolet rays and / or visible light from the outside of the mold, thereby vibrating the diaphragm Is formed.
According to a second aspect of the present invention, in the method for manufacturing a diaphragm for an electroacoustic transducer according to the first aspect, the gate is formed on one side surface of the mold and an air vent hole is formed on the opposite side surface. It is characterized by that.
According to a third aspect of the present invention, at least one of a set of molds including an upper mold and a lower mold is formed of a material that transmits ultraviolet rays and / or visible light, and the diaphragm body is formed on the lower mold. The mold is closed and the outer periphery of the diaphragm body is filled with ultraviolet and / or visible light-curing resin through the gate formed in the mold from the outside, and from the outside of the mold The resin is cured by irradiating ultraviolet rays and / or visible light, and an edge is integrally formed on the outer periphery of the diaphragm body.
According to the invention of claim 4, at least one of a set of molds including the upper mold and the lower mold is formed of a material that transmits ultraviolet light and / or visible light, and A gasket is set on one of the outer peripheral parts, the mold is closed, a resin that is cured by ultraviolet rays and / or visible light is filled from the outside through a gate formed in the mold, and ultraviolet rays are emitted from the outside of the mold. In addition, the resin is cured by irradiating visible light, and the gasket, the diaphragm body and the edge are integrally formed.
According to invention of Claim 5, it produced by the method in any one of the said Claims 1-4, It is characterized by the above-mentioned.

  According to the first and second aspects of the present invention, ultraviolet and / or visible light is applied to the photocurable resin filled in the closed mold compared with vacuum molding, pressure molding, heating and pressure molding using an upper and lower mold, and the like. Since only irradiation is required, the diaphragm can be easily manufactured. In this case, the photocurable resin is filled from the gate on the side of the mold that has been clamped in advance, and an air vent hole is provided in the opposite direction of the gate, so that the photocurable resin overflows into the clearance in the mold. In addition, it is possible to prevent a short-circuit and a bubble embedding during resin filling, and to obtain a diaphragm having good performance.

  That is, when filling the photocurable resin, there is a method of dropping the same amount of the photocurable resin as the clearance volume from above into the clearance of the lower mold and closing the upper mold, but the same amount as the clearance volume on the mold shape surface. It is difficult to drop the photocurable resin, and overflow or short circuit of the photocurable resin occurs. Moreover, in such a filling method, bubbles are embraced, which causes a problem in the performance of the speaker. On the other hand, in the present invention, the photocurable resin is filled from the gate on the side surface of the mold that has been clamped in advance.

  According to the third aspect of the present invention, since the diaphragm body having desired physical properties can be used, desired characteristics can be obtained, and the edges can be easily integrated using the optical technology according to the first and second aspects. There is an effect that can be made.

  According to the fourth aspect of the present invention, since it is easy to manufacture, it is inexpensive and does not include bubbles, so that a diaphragm having no problem in performance of the speaker can be obtained.

  Ultraviolet rays are electromagnetic waves generally having a wavelength of 10 to 400 nm, and 400 nm to 800 nm is referred to as visible light. A general ultraviolet curable resin that cures when irradiated with ultraviolet rays is composed of a base resin (monomer, oligomer), a reactive diluent, a photopolymerization initiator, an additive, and the like. It is a solid state. The radical polymerization type and the cationic polymerization type are classified from the polymerization form.

  The former radical polymerization type includes epoxy acrylate, urethane acrylate, polyester acrylate, silicone acrylate and the like as the base resin, and examples of the photopolymerization initiator include benzoin ethers, benzophenone amines, acetophenones and thioxanthones. The photopolymerization initiator reacts with specific wavelengths of ultraviolet rays and visible rays to generate free radicals, causes the base resin to polymerize, and cures in a short time of about several seconds to several tens of seconds.

  The latter cationic polymerization type includes alicyclic epoxy resin, glycidyl ether epoxy resin, epoxy acrylate, vinyl ether, etc. as the base resin, and photopolymerization initiators such as Lewis acid dianium salt, Lewis acid sulfonium salt, Lewis acid iodonium. There is salt. The photopolymerization initiator reacts with specific wavelengths of ultraviolet rays and visible rays to generate cations, causes polymerization of the base resin, and cures in a short time of about several seconds to several tens of seconds.

  Halogen lamps, metal halide lamps, high-pressure mercury lamps, ultra-high pressure mercury lamps, xenon lamps, xenon excimer lamps, xenon flash lamps (pulse emission), light-emitting diodes, etc. Radiation wavelength and energy distribution are different. These light sources are selected depending on the reaction wavelength of the photopolymerization initiator. Natural light (sunlight) can also be a reaction initiator depending on the type of photopolymerization initiator.

  These light sources can directly irradiate, irradiate with a reflecting mirror or the like, or irradiate with a fiber or the like. Thermal energy is also reduced using a heat ray cut filter, a cold mirror, or the like.

  Examples of the type of material that transmits ultraviolet rays and / or visible rays include quartz glass, soda glass, acrylic resin, and polycarbonate resin. Table 1 shows the transmittance of these ultraviolet rays and / or visible rays.

The method for producing a diaphragm for an electroacoustic transducer in the present invention has a viscosity of 20,000 [mPa · s] at 20 ° C., in which a urethane acrylate resin is a main component and a benzoin ether and a benzophenoneamine are blended as a photopolymerization initiator. After the photocurable resin that is cured by ultraviolet rays and / or visible light is clamped on the upper and lower molds preferably made of acrylic resin having a diaphragm-shaped clearance, and the mold is filled with the photocurable resin through the gate A light beam from an irradiation apparatus using an ultrahigh pressure mercury lamp as a light source was irradiated from above the mold for 5 seconds. In this case, the illuminance of the light beam after passing through the mold, 10 mW / cm ² at a wavelength of 365 nm, at a wavelength 405 nm, was 120 mW / cm ^2. Later, the upper and lower molds were opened and removed to obtain a diaphragm.

[Embodiment 1]
1 to 6 show a first embodiment of the present invention.

  In this first embodiment, first, as shown in FIG. 1, there is provided a molding die comprising a lower die 1 having a surface with irregularities corresponding to a diaphragm shape and an upper die 2 corresponding thereto. Yes. At least one of the lower mold 1 and the upper mold 2 is made of a material that transmits ultraviolet light and / or visible light, but both may be made of a transparent material.

  FIG. 2 shows a state where the lower mold 1 and the upper mold 2 are clamped. A clearance 3 for filling a photocurable resin is formed in the mold that has been clamped. This clearance preferably includes a diaphragm body portion 3a, an outer peripheral edge portion 3b, and an outer peripheral gasket portion 3c to form the diaphragm.

  Moreover, a gate 4 for resin filling is formed on one side surface of the mold, and an air vent hole is formed on the other side surface on the opposite side. The gate 4 is formed at one place in the approximate center of the junction between the clamped upper and lower molds 2 and 1. A plurality of gates 4 may be provided.

  The air vent holes are provided at substantially the same position in the reverse direction, but a plurality of air vent holes may be provided.

  A light source 5 that emits ultraviolet rays and / or visible rays is provided, for example, above the mold. If the light source 5 is provided on both the upper and lower sides and the light 6 is irradiated, the curing time can be shortened.

  Next, an example of manufacturing the diaphragm according to the present invention will be described.

  First, as shown in FIG. 3, the upper mold 2 is positioned on the lower mold 1, the mold is clamped, and the nozzle 7 for ejecting the photocurable resin is brought close to the gate 4 on the side surface of the mold.

  Next, as shown in FIG. 4, the nozzle 7 is inserted into the gate 4 and the clearance 3 in the mold is filled with the photocurable resin 8. The air present in the clearance 3 is exhausted to the outside through the air vent hole on the opposite side as the resin is filled.

  FIG. 5 shows a state in which the photocurable resin 8 is filled from the gasket portion 3c toward the edge portion 3b.

  FIG. 6 shows a state in which the photocurable resin 8 is filled up to the diaphragm body portion 3a.

  After filling the resin, as shown in FIG. 2, the resin 8 is cured by irradiating light 6 made of ultraviolet rays and / or visible rays through the light source 5 for a predetermined time.

  After the resin is cured, the mold is opened and the molded diaphragm having a predetermined shape is taken out.

  In the above, the uncured liquid resin 8 is made of inorganic fibers such as glass, carbon, aramid and the like, organic fibers, fine particle fillers such as mica and basic magnesium sulfate whisker, and ultrafine particles such as carbon nanotubes, carbon nanofibers and fullerenes. A diaphragm having various physical properties that cannot be obtained by the resin alone can be obtained by blending in advance and putting it in the clearance of the upper and lower molds and irradiating with ultraviolet rays and / or visible rays.

  Various combinations of a material to be blended and a resin material that is cured by ultraviolet rays and / or visible rays are possible, and a diaphragm having desired physical properties can be arbitrarily obtained.

  Further, by adjusting the mold closing amount, the clearance amount can be easily adjusted, and a diaphragm having a desired thickness can be produced.

[Embodiment 2]
The diaphragm is required to be highly elastic, have an appropriate internal loss, have rigidity, and be lightweight.

  In addition, the conditions required for the edge provided on the outer periphery of the diaphragm are good linearity with respect to the input signal, less likely to cause an inverse resonance phenomenon, reliable, lightweight, and easy to manufacture. Etc.

  In the above-described embodiment, the diaphragm and the edge are integrated. For this reason, manufacture is easy.

  However, since the edge and the diaphragm are made of the same material, the desired performance may not be obtained.

  On the other hand, this embodiment is characterized in that a diaphragm having desired characteristics is manufactured by easily integrating an edge with a diaphragm body separately molded in advance.

  That is, as the material of the diaphragm body, a material having a desired characteristic is selected from a paper product, a resin molded product, a metal molded product, and a composite product thereof according to the purpose and application, and this is used for the upper and lower mold clearances. The mold is closed and the mold is closed, and a photocuring resin is filled into the clearance outer peripheral portion as an edge portion through a gate, and is irradiated with light to be cured and integrated.

  In this case, the gasket may be integrated.

  In this way, a diaphragm having desired characteristics can be easily obtained, and a photo-curing resin can be appropriately filled in the same amount as in the above-described embodiment, and the diaphragm body and the edge can be When integrating, there is no need to use an adhesive, so that variations in coating amount and variations in adhesive strength do not occur, and stable characteristics can be obtained. In addition, the steps of application, bonding, and curing aging of the adhesive can be omitted, and the number of man-hours can be reduced.

  Next, a diaphragm manufacturing method according to the second embodiment will be described.

  First, as shown in FIG. 7, the diaphragm body 9 is put into a predetermined portion of the surface of the lower mold 1, and the upper mold 2 and the lower mold 1 are clamped.

  Next, as shown in FIG. 8, the nozzle 7 is brought close to the gate 4 of the upper and lower molds, and as shown in FIG. 9, the photocurable resin is passed through the gate 4 to the gasket portion 3c of the clearance outer periphery of the mold. 8 is filled.

  As shown in FIG. 10, the filled photocurable resin 8 is filled from the gasket portion 3c toward the inner edge portion 3b. In this process, the internal air is exhausted from an air vent hole (not shown).

  Then, as shown in FIG. 10, the filling is completed in a state where the edge portion 3 b is filled and the outer peripheral portion of the diaphragm body 9 is reached as shown in FIG. 11.

  Then, light is irradiated, the photocurable resin 8 is cured, and after curing, the mold is opened, and the diaphragm in which the gasket and the edge are integrated with the diaphragm body 9 may be taken out.

  In each of the above embodiments, the gasket portion 3c is provided on the outer peripheral portion of the clearance and the gasket is integrally formed, but it is needless to say that the shape of the clearance may be limited to the edge portion 3b.

  On the contrary, a metal / paper / resin molded gasket is set in the gasket portion 3c on the outer periphery of either the upper mold 2 or the lower mold 1 and then the mold is clamped. May be filled through a gate provided at an appropriate location, irradiated with light and cured, and simultaneously formed with the diaphragm body and the edge.

FIG. 2 shows half sectional views of a lower mold and an upper mold used in the first embodiment of the present invention. Explanatory drawing of the state which clamped the up-and-down type | mold of the Example same as the above is shown. Explanatory drawing of the manufacturing process of 1st Example of this invention is shown. Explanatory drawing of the next manufacturing process of 1st Example of this invention is shown. Explanatory drawing of the further next manufacturing process of 1st Example of this invention is shown. FIG. 3 is an explanatory view showing a state in which the photocurable resin is completely filled in the clearance in the mold in the manufacturing process of the first embodiment of the present invention. Explanatory drawing of the manufacturing process of 2nd Example of this invention is shown. Explanatory drawing of the manufacturing process of an Example same as the above is shown. Similarly, an explanatory view of the manufacturing process is shown. Similarly, an explanatory view of the manufacturing process is shown. The state which the photocurable resin with which the diaphragm body of the shaping | molding die was filled joined is shown.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Lower mold | type 2 Upper mold | type 3 Clearance 3a Diaphragm body part 3b Edge part 3c Gasket part 4 Gate 5 Light source 6 Light 7 Nozzle 8 Photocurable resin 9 Diaphragm body

Claims (5)

  At least one of a pair of molds consisting of an upper mold and a lower mold is formed of a material that transmits ultraviolet rays and / or visible light, the mold is closed, and the interior is formed through a gate formed in the mold. An electroacoustic characterized in that a resin that is cured by ultraviolet rays and / or visible rays is filled in the clearance from outside, and the diaphragm is molded by irradiating ultraviolet rays and / or visible rays from the outside of the mold to cure the resin. Manufacturing method of transducer diaphragm.   The method for manufacturing a diaphragm for an electroacoustic transducer according to claim 1, wherein the gate is formed on one side surface of the mold and an air vent hole is formed on the opposite side surface. A manufacturing method of a board.   At least one of a pair of molds consisting of an upper mold and a lower mold is formed of a material that transmits ultraviolet rays and / or visible light, and a diaphragm body is set on the lower mold to close the mold. The outer periphery of the diaphragm body is filled with ultraviolet and / or visible light-curing resin through the gate formed in the mold, and the resin is irradiated with ultraviolet and / or visible light from the outside of the mold. A method for manufacturing a diaphragm for an electroacoustic transducer, wherein the edge is integrally formed on the outer periphery of the diaphragm body.   At least one of a set of upper and lower molds is made of a material that transmits ultraviolet light and visible light, and a gasket is set on the outer periphery of either the upper or lower mold. The mold is closed, and a resin curable by ultraviolet rays and / or visible light is filled from the outside through a gate formed in the mold, and the resin is irradiated with ultraviolet rays and / or visible light from the outside of the mold. A method for manufacturing a diaphragm for an electroacoustic transducer, wherein the gasket, the diaphragm body and the edge are integrally formed by curing.   An electroacoustic transducer diaphragm manufactured by the method according to claim 1.

Images