JP2006013985A - Facility of producing diaphragm for speaker, diaphragm for speaker produced therewith and speaker employing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a facility for producing an excellent diaphragm for speaker which has no occurrence of a problem such as tear, can be formed with high accuracy even in the case of a diaphragm having a complicated shape, and can establish compatibility between performance improvement as a speaker and satisfactory productivity. <P>SOLUTION: The production facility of this diaphragm for speaker gradually controls the pressure and flow rate of compressed air at the time of pressure forming to form a sheet-like film material. The facility is configured so as to include at least a die 8 for forming the diaphragm into a predetermined shape, a means 5 for jetting compressed air and a pressure control means 13 of the compressed air. In the pressure control means, the pressure of the compressed air during injecting the compressed air can be arbitrarily set. That means, it is possible to freely adjust the pressure and a time. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a production facility for a speaker diaphragm made of resin, mainly among speakers used in various acoustic devices, and a diaphragm for a speaker obtained using the same.

  Conventionally, paper, metal, resin, etc. have been used as speaker diaphragms, and they are selected and used as appropriate according to the characteristics and applications of each material. In view of the above, a diaphragm using resin is often used.

  In addition, speaker diaphragms using such resins are produced by injection molding methods for those with a relatively large diameter and thickness, but this injection molding method is highly accurate and has a complicated shape. However, it is difficult for a thin material, and the productivity is poor because a long molding time is required.

  In addition, for those with a small diameter and a small thickness, a method of molding with a mold using a resin film is generally used. When molding with this mold, the resin film is molded into a predetermined diaphragm shape. Pressure forming or vacuum forming is performed using a pair of male and female molds that have been processed to perform the same process, and one mold that has been processed to form a resin film into a predetermined diaphragm shape. There is a method.

  In recent market demands, there are strong demands for cost reduction and high productivity. For this reason, particularly in the production equipment for small speaker diaphragms, production equipment that performs pressing using a pair of male and female molds. In addition, production facilities that perform compressed air forming or vacuum forming using one mold are becoming mainstream, and among these, one mold is used rather than production equipment that performs pressing using a pair of male and female dies. Production facilities that perform compressed air molding or vacuum molding are superior in terms of cost reduction and high productivity, and these are becoming mainstream in production facilities for speaker diaphragms using resin films. This is not an exaggeration.

  FIG. 4 is a block diagram showing a conventional speaker diaphragm production facility that performs compression molding using such a single mold, and FIG. 5 shows a speaker obtained by the speaker diaphragm production facility. Sectional drawing of the diaphragm for use is shown.

  As shown in FIG. 4, it includes at least a mold 8 for forming a diaphragm in a predetermined shape and a compressed air discharge means 5.

  In more detail, in FIG. 4, 1 is a booster, 2 is supply air, 3 is a booster, 4 is a pressure control valve, 5 is a discharge valve, 6 is supply air, 7 is a stage, 8 is a mold, Reference numeral 9 denotes a heater, 10 denotes a temperature sensor, 11 denotes a heating block, and 12 denotes a pressure sensor.

  With this production facility, a sheet-like film material prepared in advance as a diaphragm material is put into the stage 7, and is clamped by the stage 7 and the mold 8 while applying temperature by mold heating, and a constant pressure is applied by air pressure. By adding, it was formed along the mold 8.

  After that, the mold was opened when the temperature was lowered and the shape was stabilized by cooling the mold, and the diaphragm molded product was taken out by releasing from the mold 8.

  Thereafter, the outer shape of the diaphragm was punched by a punching die to obtain the diaphragm 17 shown in FIG.

  Here, when pressure is applied by air pressure, molding is performed along the mold by applying a pressure of 0.8 MPa or less without changing for a certain time.

For example, Patent Literature 1 and Patent Literature 2 are known as prior art literature information related to the invention of this application.
Japanese Patent Laid-Open No. 55-162696 Japanese Patent Publication No. 7-101953

  However, in the conventional speaker diaphragm production equipment that performs pressure air forming using the above-mentioned one mold, it is difficult to obtain a complicated shape and accuracy because a sheet-like film material prepared in advance is formed. Also, strict management of molding time and molding temperature is necessary. If this management condition is poor, the stability of the shape deteriorates due to the occurrence of springback, which causes quality problems such as deformation, shape distortion, and dimension loss. It was something to do.

  In addition, in order to ensure complex shape and accuracy, as well as shape stability, it is necessary to increase the air pressure during pressure forming, keep it in the mold without floating, and maintain heating for a certain period of time, When the pressure of the air is increased, when the material thickness is thin, the viscosity suddenly decreases in the vicinity of Tg (glass transition point), so that there is a quality problem that the film material is torn.

  In addition, even after molding, when the molding is not easy, a complicated or deep portion tends to deform due to the occurrence of springback and return to a state close to the original sheet shape.

  The present invention solves the above-described problems, and even a diaphragm having a complicated shape can be molded accurately without causing problems such as tearing, and can achieve both improvement in performance and good productivity as a speaker. An object of the present invention is to provide an excellent speaker diaphragm production facility.

  In order to solve the above-described problems, the speaker diaphragm production facility of the present invention is a speaker diaphragm production facility in which a film is formed by pressure forming to obtain a diaphragm. In molding, the pressure and flow rate of the compressed air are controlled stepwise to form.

  As described above, the speaker diaphragm production facility according to the present invention has a complicated diaphragm shape by forming a sheet-like film material by stepwise controlling the pressure and flow rate of compressed air during compression molding. Even if it exists, it can shape | mold accurately.

  And by controlling finely the pressure and flow rate of compressed air according to the physical property and moldability of the film material to be used, it can be formed without difficulty and the residual stress can be reduced.

  Therefore, it is possible to eliminate the tearing of the sheet-like film material, reduce the springback force to return to the original sheet shape, and realize the improvement of the dimension and shape stability, quality and reliability of the diaphragm. Can do.

  In addition, it is possible to improve various characteristics such as sound pressure frequency characteristics and distortion characteristics of speakers using these diaphragms.

  Furthermore, since the thickness of the diaphragm can be set thin, it can be a diaphragm suitable for downsizing and high sound pressure of the speaker.

  As described above, the present invention can provide an excellent speaker diaphragm and speaker capable of realizing improvement in performance and quality, and its industrial value is very large.

(Embodiment 1)
Hereinafter, the first aspect of the present invention will be described with reference to the first embodiment.

  FIG. 1 is a block diagram showing production equipment for speaker diaphragms according to Embodiment 1 of the present invention.

  As shown in FIG. 1, it includes at least a mold 8 that forms a diaphragm in a predetermined shape, a compressed air discharge means 5, and a compressed air pressure control means 13.

  Here, the point different from the conventional one is that a pressure control means 13 for compressed air is provided.

  In more detail, in FIG. 1, 1 is a booster, 2 is supply air, 3 is a booster, 5 is a discharge valve, 6 is supply air, 7 is a stage, 8 is a mold, 9 is a heater, 10 is A temperature sensor, 11 is a heating block, 12 is a pressure sensor, and 13 is a pressure control means.

  Conventionally, a pressure control valve was provided and the pressure could be set, but only a constant pressure could be applied during the injection of compressed air.

  In contrast, the pressure control means according to the present invention can arbitrarily set the pressure of the compressed air during the injection of the compressed air. That is, the pressure and time can be freely adjusted.

  With this production facility, a sheet-like film material prepared in advance as a diaphragm material is put into the stage 7 and is clamped by the stage 7 and the mold 8 while being heated by mold heating, and stepwise by air pressure. Molding is performed along the mold 8 by applying pressure.

  Thereafter, the mold is opened when the temperature is lowered and the shape is stabilized by cooling the mold, and the diaphragm molded product is taken out by releasing from the mold 8.

  Thereafter, the outer shape of the diaphragm is punched by a punching die to obtain a diaphragm.

  Here, as a method of applying pressure by the air pressure, conventionally, the pressure of compressed air is always maintained at a constant value. However, the present invention performs molding by controlling the pressure of compressed air stepwise.

  The compressed air is divided into multiple stages such as injecting primary compressed air, then injecting secondary compressed air by changing the pressure, and injecting tertiary compressed air by changing the pressure. The pressure is controlled to form.

  After that, when the temperature is lowered and the shape is stabilized by cooling the mold, the mold is opened, the diaphragm formed by releasing from the mold is taken out, the outer shape of the diaphragm is punched out by the punching mold, and the diaphragm Have gained.

  Here, as a method of changing the pressure of the compressed air, for example, in the case of a material that is likely to break the material when the pressure is suddenly applied or a thin material, the primary compressed air is injected at a low pressure. Next, it is effective to sequentially increase the pressure, such as injecting secondary compressed air at an intermediate pressure and then injecting tertiary compressed air at a higher pressure.

  In this way, by controlling the pressure of compressed air in multiple stages, molding can be performed while reducing the load applied to the material by forming the material that is likely to break or thin material little by little. And the occurrence of material breakage can be prevented.

  Furthermore, even if it is a complicated diaphragm shape, it can shape | mold accurately without relying on injection molding or male and female press die shaping.

  In this case, the temperature control of the compressed air is linked to the pressure of the compressed air, and the temperature is set to an optimum temperature for the material to be molded, so that it becomes more effective and the molding can be performed with higher accuracy. .

  By adopting this configuration, even a complicated diaphragm shape can be molded with higher accuracy, the tear of the sheet-like film material can be eliminated, and the dimensions and shape stability of the diaphragm, Improvements in quality and reliability can be realized.

  In the above embodiment, the manufacturing method for sequentially increasing the pressure of compressed air in three stages has been described. However, the present invention is not limited to this embodiment, and it is effective if the pressure of compressed air is two or more. .

  Also, the method for controlling the pressure of the compressed air is not limited to the method of increasing the pressure sequentially, and can be set freely, such as a method of decreasing the pressure or repeating the height, and the control pattern is molded. It is desirable to set an optimum pattern according to the characteristics of the material.

  The same effects as those of the manufacturing method described above can be obtained, and as a different means, a method of forming by controlling the flow rate of the compressed air stepwise can be used.

  Since this manufacturing method also has the same effect as the method of forming by controlling the pressure of compressed air in steps, the detailed description thereof will be omitted, but the flow rate is stepped instead of the pressure described above. The same effect can be obtained by controlling automatically, that is, by controlling the pressure while changing the time.

  If it is the structure of the production facility of FIG. 1, it is the production facility which replaced the 13 pressure control means with the flow control means.

  Moreover, it can be set as the production equipment which controls finely using both a pressure control means and a flow control means.

  And by controlling finely the pressure and flow rate of compressed air according to the physical property and moldability of the film material to be used, it can be formed without difficulty and the residual stress can be reduced.

  Therefore, it is possible to eliminate the tearing of the sheet-like film material, reduce the springback force to return to the original sheet shape, and realize the improvement of the dimension and shape stability, quality and reliability of the diaphragm. Can do.

  Therefore, it is possible to use this production facility according to the characteristics and physical properties of the material to be molded, as well as the form and performance of the manufacturing method, and further control the flow rate and pressure in combination with the pressure control method described above. It is.

  By using this production facility, it is possible to prevent molding with higher accuracy and prevent material breakage, and to further improve the dimensional and shape stability, quality, and reliability of the diaphragm.

  In addition, by forming the compressed air pressure at a maximum pressure of 0.8 MPa or more, a sheet-like film material can be molded more strongly along the mold, resulting in complex diaphragm shapes and deep vibrations. Even if it is plate shape, it can shape | mold accurately and shape stability can also be improved.

  Conventionally, if a pressure of 0.8 MPa or more was applied without changing for a certain period of time, there were very many cases where fracture occurred depending on the material and the thickness of the material. It is possible to make an effective method by combining with production equipment that can be controlled.

  In addition, the material temperature can be set to the optimum value by heating and forming the film before the air pressure forming, and the material breakage can be prevented in the same manner as described above, and the complicated diaphragm shape and deep diaphragm shape can be prevented. Even so, it can be molded with high accuracy and the shape stability can be improved.

  As this film heating means, a means for heating by a mold, that is, a method for raising the material temperature by heating the mold, or a method for heating the material by providing a preheating step in advance is used. It may be used.

  Further, the mold may be provided with cooling means.

  By adopting this configuration, it is possible to promote a decrease in temperature after molding, shorten the time until the shape of the diaphragm is stabilized, and improve the productivity of the diaphragm.

(Embodiment 2)
The second aspect of the present invention will be described below with reference to the eighth aspect of the present invention.

  FIG. 2 shows a cross-sectional view of a speaker diaphragm according to an embodiment of the present invention.

  FIG. 2 shows a loudspeaker diaphragm 27 obtained by the loudspeaker diaphragm production facility according to any one of claims 1 to 7.

  As described in the first embodiment, the speaker diaphragm 27 can control the pressure and flow rate of compressed air in a stepwise manner with a sheet-like film material by the speaker diaphragm production facility of the present invention. In this way, a diaphragm having a complicated shape or a diaphragm having a deep shape is obtained by molding along the mold.

  Thereby, a diaphragm with high dimensional accuracy, a diaphragm without tearing of the film material, and a diaphragm capable of improving the shape stability after molding can be obtained.

(Embodiment 3)
Hereinafter, the invention described in the ninth aspect of the present invention will be described with reference to the third embodiment.

  FIG. 3 shows a cross-sectional view of a speaker according to an embodiment of the present invention.

  As shown in FIG. 3, a magnetized magnet 21 is sandwiched between an upper plate 22 and a yoke 23 to constitute a magnetic circuit 24.

  A frame 26 is coupled to the yoke 23 of the magnetic circuit 24, a diaphragm 27 of the present invention is bonded to the peripheral portion of the frame 26, and a voice coil 28 for driving the diaphragm 27 is coupled to the diaphragm 27. .

  The voice coil 28 is coupled so as to fit into the magnetic gap 25 of the magnetic circuit 24 to constitute a speaker.

  Here, the diaphragm 27 is configured using the diaphragm according to claim 8. In other words, even a complex shape or deep shape diaphragm is composed of a highly reliable diaphragm with high dimensional accuracy, no tearing of the film material, and improved shape stability after molding. Yes.

  With this configuration, the speaker can achieve low distortion and high linearity, and a high-performance speaker that can reproduce good sound quality can be realized.

  Further, it is possible to improve productivity as a speaker and improve quality and reliability.

  As described above, the effect when the diaphragm 27 of the present invention is used for a speaker has been described. However, the usage range of the diaphragm 27 is not limited to the speaker, and may be an electroacoustic transducer such as a receiver or a microphone. Can be used for all.

  The diaphragm for a speaker according to the present invention includes a diaphragm for an electroacoustic transducer and an electroacoustic transducer such as a speaker that are used in various acoustic devices that require higher sound quality and improved productivity and quality of the diaphragm. It can be applied to other uses.

The block diagram which shows the production equipment of the diaphragm in one embodiment of this invention Sectional drawing of the diaphragm in one embodiment of this invention Sectional drawing of the speaker in one embodiment of this invention Block diagram showing conventional diaphragm production equipment Cross-sectional view of a conventional diaphragm

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Booster 2 Supply air 3 Booster 4 Pressure control valve 5 Discharge valve 6 Supply air 7 Stage 8 Mold 9 Heater 10 Temperature sensor 11 Heating block 12 Pressure sensor 13 Pressure control means 17 Vibration plate 21 Magnet 22 Upper plate 23 Yoke 24 Magnetic Circuit 25 Magnetic gap 26 Frame 27 Diaphragm 28 Voice coil

Claims (9)

A speaker diaphragm production facility for obtaining a diaphragm by forming a film by pressure forming, at least a mold for forming the diaphragm into a predetermined shape, a discharge means for compressed air, and pressure control of the compressed air Means for producing a speaker diaphragm capable of controlling the pressure of compressed air stepwise or arbitrarily. A speaker diaphragm production facility for obtaining a diaphragm by forming a film by pressure forming, at least a mold for forming the diaphragm into a predetermined shape, a discharge means for compressed air, and a flow control of the compressed air Means for producing a speaker diaphragm capable of controlling the flow rate of compressed air stepwise or arbitrarily. A speaker diaphragm production facility comprising both the first and second aspects. The production equipment for a speaker diaphragm according to any one of claims 1 to 3, wherein the compressed air has a maximum pressure of 0.8 MPa or more. The production facility for a speaker diaphragm according to any one of claims 1 to 4, further comprising a mold heating means. The production facility for a speaker diaphragm according to any one of claims 1 to 5, further comprising a film heating unit. The speaker diaphragm production facility according to any one of claims 1 to 6, further comprising a mold cooling means. A loudspeaker diaphragm obtained by the production equipment for a loudspeaker diaphragm according to claim 1. A frame coupled to the magnetic circuit, a diaphragm coupled to the outer periphery of the frame, and a voice coil coupled to the diaphragm and part of which is disposed in the magnetic gap of the magnetic circuit. The speaker is configured by using the diaphragm according to claim 8.

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