JP4588489B2 - Speaker diaphragm and manufacturing method thereof - Google Patents

Description

  The present invention relates to a speaker diaphragm and a method for manufacturing the same.

The physical properties required for speaker diaphragms are large specific elastic modulus (E / ρ), specific bending rigidity (E / ρ ³ ), moderate internal loss, strong mechanical fatigue, and weather resistance. It ’s good. Furthermore, in recent years, waterproofing has become one of the important characteristics, especially for in-vehicle use. In order to respond to such demands, materials such as various metals, ceramics, synthetic resins, synthetic fibers, natural cellulose fibers, and more recently microbial cellulose fibers using biotechnology have been proposed and used various processing methods. Manufactured.

  In such a diaphragm for a speaker, a synthetic resin diaphragm can be cited as one having good productivity and excellent environmental resistance such as water resistance. This synthetic resin diaphragm improves sound quality by incorporating fibers such as carbon fibers in order to improve the specific elastic modulus of thermoplastic resin such as polypropylene (PP) having a relatively large internal loss. It is mainly manufactured by an injection molding method in which a resin is filled in a molding gap of a molding die composed of a male die and a female die.

  Such a synthetic resin diaphragm by injection molding has a drawback in that the degree of freedom in design is low because the types and amounts of fibers that can be mixed are limited in the manufacturing process. In addition, when the foamed layer is formed inside the synthetic resin diaphragm to reduce the apparent density to improve the specific elastic modulus, the foamed layer reduces the mechanical rigidity of the diaphragm, or There arises a problem that the appearance is impaired.

  In order to solve such problems of the synthetic resin diaphragm, the diaphragm is made of multiple layers of different materials, and a surface layer called a skin layer is formed on the surface of the low-density resin layer to increase the strength. Alternatively, it has been proposed to have a structure in which the skin layer bears properties such as environmental resistance or appearance.

  For example, Patent Document 1 below describes a diaphragm including a surface layer made of bacterial cellulose and an injection material (resin layer) made of polypropylene, and Patent Documents 2 to 4 listed below describe a foam layer and an unfoamed material. A diaphragm with a skin layer consisting of layers is described. Patent Document 5 listed below is a diaphragm in which a fiber having a length of 3 mm to 50 mm is contained in a resin component, and fibers that are radially oriented from the center to the peripheral direction are fixed in the resin component. A surface layer and an intermediate layer in which fibers oriented in a different direction are fixed to a resin component are described.

JP 2000-4496 A Japanese Patent No. 3238693 Japanese Patent No. 3135482 JP 2002-369286 A JP 2004-15194 A

  When forming such a diaphragm having a multilayer structure, as shown in FIG. 1, this diaphragm is cut by a diaphragm main body portion J1a functioning as a diaphragm and a cut surface CC after being formed and removed. The diaphragm base material formed by the removal portions J1b and J1c is molded and cooled and solidified after the vibration plate base material taken out from the molding die after molding, and then the above-described cutting and removal portions J1b and J1c are processed (FIG. 1). The cross section of the diaphragm base material is shown, and the cross-sectional enlarged view is shown in the circles with a one-dot broken line).

  At this time, in the vibration plate having a multilayer structure composed of the surface layer a and the resin layer b, a regular shape along the mold is maintained in the molding die as shown in FIG. At the stage of cooling and solidifying after taking out from the mold, there is a problem that the diaphragm main body J1a is curved and deformed due to the difference in shrinkage between the surface layer a and the resin layer b as shown in FIG. .

  This invention makes it an example of a subject to cope with such a problem. That is, it is an object of the present invention to prevent deformation that occurs after removal from the molding die for a diaphragm having a multilayer structure composed of a surface layer and a resin layer.

  In order to achieve such an object, the speaker diaphragm and the method for manufacturing the speaker diaphragm according to the present invention include at least the configurations according to the following independent claims.

[Claim 1]
A diaphragm having a multilayer structure of a surface layer and a resin layer, wherein the diaphragm is formed from a diaphragm substrate formed by molding, and is arranged around the outer peripheral edge of the diaphragm substrate on the central axis of the diaphragm. molded portion extending extending along the direction forming Rutotomoni, the vibrating plate substrate is made of cut and removed portion and to be removed by the cutting process and the diaphragm main body that forms the diaphragm, the extending molding The part is formed in the cutting and removing part extending from the outer peripheral edge of the diaphragm main body part .

[Claim 5 ]
A method of manufacturing a diaphragm having a multilayer structure of a surface layer and a resin layer, the method comprising: forming a diaphragm base material having the surface layer and the resin layer by a molding die, wherein the diaphragm An extended molded part extending in a direction along the center axis of the diaphragm is formed in the vicinity of the outer peripheral edge of the base material, and the extended molded part is cut and removed after the diaphragm base material is formed. Method for manufacturing a diaphragm for an automobile.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 2 is an explanatory view for explaining a speaker diaphragm according to an embodiment of the present invention (FIG. 2A is a cross-sectional view showing one embodiment, and FIG. 2B is another embodiment). It is a cross-sectional view showing a form, and an enlarged cross-sectional view is shown in a circle indicated by a dashed line in the figure).

The diaphragm according to the embodiment of the present invention has a multilayer structure of a surface layer 1a and a resin layer 1b ₁ or 1b ₂ (in the example shown, a two-layer structure consisting of a surface layer 1a and a resin layer 1b ₁ or 1b ₂ ). Although an example is shown, a surface layer 1a may be provided on both the front and back surfaces, or a multilayer structure of three or more layers may be used), and the diaphragm main body 1A that forms the diaphragm and the cut surface CC after forming are cut. It is formed from the diaphragm base material 1 which consists of the cutting removal parts 1B ₁ and 1B ₂ to be removed. FIG. 4A shows an example in which the resin layer 1b ₁ is formed by a foam layer, and FIG. 4B shows an example in which the resin layer 1b ₂ is formed by a non-foamed layer.

Here, a feature of the diaphragm according to the embodiment of the present invention is that an extension molding portion 1c extending in the direction along the central axis (symmetric axis) O of the diaphragm is formed in the vicinity of the outer peripheral edge of the diaphragm base 1. There is. The extended molded portion 1c does not need to be formed completely parallel to the central axis O, and may be formed so as to be substantially parallel and have a slight inclination (for example, a range of a draft of 2 to 5 °). . The drawings, there is shown an example of forming the cut and removed portion 1B ₁ extending the extending molding portion 1c from the outer peripheral edge of the diaphragm main body 1A, not limited to this, in the vicinity of the outer peripheral edge of the diaphragm main body 1A It can also be formed.

In addition, the extended molding portion 1c is formed in a direction opposite to the direction of the curved deformation caused by the difference in contraction rate between the surface layer 1a and the resin layers 1b ₁ and 1b ₂ when the diaphragm base material 1 is cooled and solidified after molding. ing. In the illustrated example, the resin layers 1b ₁ and 1b ₂ having a large shrinkage rate are provided on the lower layer side, and the extended molding portion 1c is in a state of rising upward, but the resin layers 1b ₁ and 1b ₂ having a large shrinkage rate are provided. Is provided on the upper layer side, the extended molded portion 1c is formed to fall downward.

  According to the diaphragm according to such an embodiment, even when there is a difference in the shrinkage rate of each layer of the multilayer structure when the diaphragm base material 1 is cooled and solidified after molding, the presence of the above-described extension molded portion 1c is present. Therefore, the deformation stress is suppressed, and the bending deformation of the diaphragm main body 1A as shown in FIG. 1B does not occur.

In particular, the diaphragm base 1 is composed of a diaphragm main body 1A that forms a diaphragm and cutting removal parts 1B ₁ and 1B ₂ that are removed by a cutting process, and the extended molding part 1c is disposed outside the diaphragm main body 1A. When formed in the cut and removed portion 1B ₁ extending from the peripheral edge, the extended molded portion 1c can be formed regardless of the form of the diaphragm main body 1A. The problem of bending deformation can be avoided.

The surface layer 1a in the embodiment of the present invention can be formed of a woven fabric such as various fibers, a film, or a metal, and is formed by forming a part of the resin layer 1b ₁ as an unfoamed layer or a cured layer. can do. In addition, the resin layers 1b ₁ and 1b ₂ in the embodiment of the present invention may be any type of resin layer such as a mixture of various fibers, a foamed layer or an unfoamed layer, in short, a surface layer. 1a and the resin layer 1b _1, 1b ₂ as long as such difference in shrinkage between at cooling and solidification occurs between the.

FIG. 3 is a cross-sectional view showing a molding die for a speaker diaphragm according to an embodiment of the present invention. In this molding die 10, a molding gap 10 </ b> A is formed between the male die 11 and the female die 12, and the above-described diaphragm base 1 is molded by the molding gap 10 </ b> A. Then, the molding die 10 according to the embodiment of the present invention, the molding gap 10A has a gap portion 10A _L to form shaped portions 1c extending described above.

That is, the example shown, in succession to the portion forming the diaphragm main body 1A as described above at 10 of the forming gap, the gap portion 10A _L described above in the direction along the center axis O are formed. Further, in the illustrated example, a filling hole 10B is formed on the female mold 12 side, and resin is filled into the molding gap 10A from this filling hole 10B.

  According to the molding die 10 according to such an embodiment, since the above-described extension molding portion 1c can be formed as a part of the diaphragm base 1, the diaphragm main body is not particularly added. An extended molded portion 1c that prevents the curved deformation of the portion 1A can be formed. That is, when the diaphragm base material 1 is molded using the molding die 10 according to the embodiment of the present invention, it is possible to form a high-quality diaphragm base material 1 that is not curved and deformed even during cooling and solidification after molding. .

4-6 is explanatory drawing explaining the manufacturing method of the diaphragm for speakers which concerns on each embodiment of this invention. The manufacturing method of the speaker diaphragm according to the embodiment of the present invention includes a step of forming the diaphragm base 1 having the surface layer 1a and the resin layers 1b ₁ and 1b ₂ by the molding die 10 described above. In this process, an extended molded portion extending in the direction along the center axis O of the diaphragm is formed near the outer peripheral edge of the diaphragm base 1, which is realized in various forms as shown below. Can do.

The embodiment shown in FIG. 4 is to form a surface layer 1a is loaded to the surface layer material 1a ₀ which is previously molded in the molding die 10. That is, as shown in FIG. 6 (a), by placing the surface layer member 1a ₀ molded in advance in the surface shape of the diaphragm substrate 1 between the male die 11 and female die 12, As shown in FIG. 2B, for example, the surface layer material 1a ₀ is attached to the forming gap forming portion on the male mold 11 side. In this state, as shown in FIG. 3C, the male mold 11 and the female mold 12 are fitted together, and for example, the resin is filled into the molding gap from the female mold side.

According to such a manufacturing method, since the surface layer material 1a ₀ is pre-shaped into the surface shape of the diaphragm base material 1 and then insert-molded, the shape of the surface layer 1a can be more accurately formed, and the desired shape The diaphragm substrate 1 can be obtained, and the diaphragm substrate 1 without deformation after molding can be obtained.

In the embodiment shown in FIG. 5, the surface layer 1 a is formed by simultaneously molding the unshaped surface layer material 1 a ₀ in the molding die 10. That is, as shown in FIG. 4A, an unmolded surface layer material 1a ₀ is disposed between the male mold 11 and the female mold 12, and as shown in FIG. in a state fitted to the male mold 11 and female mold 12 to place the surface layer material 1a ₀ in the forming gap. In this state, as shown in FIG. 6C, for example, a resin is filled into the molding gap from the female mold side, and the surface layer 1a and the resin layers 1b ₁ and 1b ₂ are simultaneously placed in the molding gap. Mold.

  According to such a manufacturing method, a diaphragm having a multilayer structure can be obtained by the same process as in the case of a single layer, and the diaphragm substrate 1 without deformation after molding can be obtained.

In the embodiment shown in FIG. 6, the resin layer ₁ b ₁ is formed as a foam layer in the molding die 10. That is, as shown in FIG. 6 (a1), (b1) or (a2), (b2), similar to the embodiment shown in FIG. 4 or FIG. The surface layer material 1a ₀ is disposed in the molding gap with the 12 being fitted together. In this state, as shown in FIG. 6 (c), for example, a resin containing a foaming agent is filled into the molding gap from the female mold side, and before this resin is completely solidified, FIG. 6 (d) As shown in Fig. 4, the mold is opened immediately and the filled resin is foamed.

According to such a manufacturing method, as shown in FIG. 7 (enlarged cross-sectional view of the speaker diaphragm), the surface layer 1a and the resin layer 1b ₁ are formed, and the resin layer 1b ₁ is unfoamed on both the front and back surfaces. The skin layer 1b _1s and the foam layer 1b _1m are formed inside.

Then, such after molding the diaphragm substrate 1 by the respective embodiments, by performing a cutting process of cutting and removing portions 1B _1, 1B ₂ described above, to obtain a vibration plate made of a diaphragm main body 1A. At this time, when forming the molded portion 1c extending previously described cut and removed portion 1B _1, regardless of the shape of the diaphragm main body 1A, it is possible to obtain a high quality diaphragm substrate 1.

  As described above, according to the speaker diaphragm, the speaker diaphragm manufacturing method, and the speaker diaphragm molding die according to the embodiment of the present invention, the multilayer diaphragm composed of the surface layer and the resin layer is used. On the other hand, it becomes possible to prevent the deformation | transformation which arises after taking out from a shaping die. The diaphragm having a multilayer structure can increase the degree of design freedom of the diaphragm made of synthetic resin, and demands for improvement of the specific elastic modulus of the diaphragm and improvement of mechanical rigidity, appearance, or environmental resistance. At the same time, a satisfactory high-quality diaphragm can be obtained.

It is explanatory drawing explaining the subject of a prior art. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1A is a cross-sectional view showing one embodiment of the speaker diaphragm according to the embodiment of the present invention, and FIG. There is an enlarged cross-sectional view in a circle indicated by a dashed line in the figure). It is sectional drawing which shows the shaping die of the diaphragm for speakers which concerns on embodiment of this invention. It is explanatory drawing explaining the manufacturing method of the diaphragm for speakers which concerns on each embodiment of this invention. It is explanatory drawing explaining the manufacturing method of the diaphragm for speakers which concerns on each embodiment of this invention. It is explanatory drawing explaining the manufacturing method of the diaphragm for speakers which concerns on each embodiment of this invention. It is a cross-sectional enlarged view of the diaphragm for speakers.

Explanation of symbols

1 diaphragm substrate 1A diaphragm body portion 1B _1, 1B ₂ cut off portion 1a surface layer 1b _1, 1b ₂ resin layer 1b _1s skin layer 1b _{1 m} foamed layer 1c extending molding portion 10 molding die 10A forming gap 10A _L Gap part 11 Male mold 12 Female mold O Center axis

Claims (8)

A diaphragm having a multilayer structure of a surface layer and a resin layer,
The diaphragm is formed from a diaphragm substrate that is molded,
The diaphragm extending molding portion extending in a direction along the central axis of the diaphragm in the vicinity of the outer peripheral edge of the substrate is formed Rutotomoni, the diaphragm substrate, a diaphragm main body that forms the diaphragm A speaker diaphragm , comprising: a cutting and removing portion that is removed by a cutting process, wherein the extending and forming portion is formed in the cutting and removing portion extending from an outer peripheral edge of the diaphragm main body portion .   The extension molding part is formed in a direction opposite to a direction of curved deformation caused by a difference in shrinkage between the surface layer and the resin layer at the time of cooling and solidification after molding. A diaphragm for speakers. The speaker diaphragm according to claim 1 or 2 , wherein the diaphragm has a two-layer structure of the surface layer and the resin layer. The speaker diaphragm according to any one of claims 1 to 3 , wherein the resin layer is a foam layer. A method of manufacturing a diaphragm having a multilayer structure of a surface layer and a resin layer,
Forming a diaphragm base material having the surface layer and the resin layer by a molding die;
In this step, an extended molded part extending in the direction along the central axis of the diaphragm is formed in the vicinity of the outer peripheral edge of the diaphragm base , and the extended molded part is cut and removed after the diaphragm base is molded. A method for manufacturing a speaker diaphragm. 6. The method for manufacturing a speaker diaphragm according to claim 5 , wherein the surface layer is formed by loading a previously formed surface layer material into the molding die. 6. The method for manufacturing a speaker diaphragm according to claim 5 , wherein the surface layer is formed by simultaneously molding an unshaped surface layer material in the molding die. The method for manufacturing a speaker diaphragm according to claim 6 or 7 , wherein the resin layer is formed as a foam layer in the molding die.

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