JP2014187642A - Diaphragm for speaker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To strengthen adhesive forces between layers of a diaphragm and prevent peeling in a diaphragm for a speaker composed of a sheet making laminate.SOLUTION: Two sheet making bodies are strongly brought in contact and are prevented from peeling by configuring a diaphragm by laminating a sheet making body of short fibers and a sheet making body of long fibers.

Description

  The present invention relates to a diaphragm used for a speaker.

  2. Description of the Related Art A speaker device configured by superposing a plurality of different paper products is known. For example, in Patent Document 1, a semi-dried inner cone paper in a semi-dried state is laminated between a paper-made semi-dried inner cone paper and an outer cone paper, and they are heated and pressurized. A method is described.

JP-A-3-210897

  However, in the speaker diaphragm manufactured by the method described in Patent Document 1, since the cone papers are laminated in a semi-dry state, hydrogen bonding between fibers is difficult to occur, and peeling occurs between the laminated cone papers. There is a problem.

  Examples of the problem to be solved by the present invention include the above. SUMMARY OF THE INVENTION An object of the present invention is to provide a loudspeaker diaphragm formed by laminating paper products, thereby strengthening the adhesion between the diaphragm layers and suppressing delamination.

  The invention according to claim 1 is a diaphragm for a speaker, comprising a entangled body of a first fiber and an entangled body of a second fiber, wherein the entangled body of the first fiber and the second fiber The fiber entangled body is integrated.

It is a figure which shows the structure of the diaphragm for speaker apparatuses. It is a figure which shows the structure of the diaphragm which concerns on an Example. It is a figure which shows the manufacturing method of the diaphragm which concerns on an Example. It is a figure which shows the manufacturing method of the diaphragm which concerns on a comparative example. The characteristic of the diaphragm which concerns on a specific example and a comparative example is shown.

  In a preferred embodiment of the present invention, the speaker diaphragm includes an entangled body of the first fibers and an entangled body of the second fibers, the entangled body of the first fibers and the second fibers. The entangled body is integrated.

  In the above diaphragm, the first entangled body and the second entangled body can be firmly adhered by using the first fiber and the second fiber. That is, the entanglement area | region of a 1st fiber and a 2nd fiber is comprised, and peeling with the entanglement body of a 1st fiber and the entanglement body of a 2nd fiber can be suppressed. Preferably, the length of the first fiber is less than the length of the second fiber.

  In one aspect of the diaphragm, the density of the second entangled body is greater than the density of the first entangled body. In this embodiment, the first fiber is restrained by the second fiber product to suppress peeling.

  In another aspect of the diaphragm, the porosity of the entangled body of the second fibers is smaller than the porosity of the entangled body of the first fibers. In this embodiment, the second fiber paper is tightened and the first fibers are restrained by the second fiber paper.

  In another preferred example, the first fiber is less rigid than the second fiber. In yet another preferred example, the first fiber is thinner than the second fiber. In still another preferred example, the first fiber has a lower beating degree than the second fiber.

  In another aspect of the above diaphragm, in the entanglement region, the first fiber protrudes from the entangled body of the first fiber toward the entangled body of the second fiber. In this aspect, the first fiber is likely to enter by the entangled body of the second fiber, and the first fiber is easily restrained by the entangled body of the second fiber.

  A speaker device can be constituted by the above-described speaker diaphragm, voice coil, magnetic circuit, and frame. In addition, this speaker device can be mounted on an electronic device.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

[Configuration of diaphragm]
FIG. 1 shows a configuration of a speaker device according to an embodiment. The speaker device 100 includes a magnetic circuit 1 formed by a magnet 1A, a plate 1B, and a yoke 1C, a voice coil 3 that is disposed in a magnetic gap of the magnetic circuit 1 and wound around a voice coil bobbin 2, and an inner peripheral portion is a voice. And a diaphragm 10 fixed to the coil bobbin 2. The outer peripheral portion of the diaphragm 10 is fixed to the speaker frame 7 via the edge 5 and the gasket 6. The voice coil bobbin 2 is fixed to the speaker frame 7 by a damper 8, and the opening of the voice coil bobbin 2 is covered with a center cap 9.

  FIG. 2A is a cross-sectional view illustrating the layer configuration of the diaphragm 10. In FIG. 2A, the direction of acoustic radiation from the speaker is indicated by an arrow 9. The diaphragm 10 is formed by laminating the papermaking 11 and the papermaking 2. The paper products 11 and 12 are each made of paper and are cone paper constituting the diaphragm 10. The paper product 11 is formed of short fibers, and the paper product 12 is formed of fibers longer than the paper product 11. In general, the diaphragm preferably has a high Young's modulus in that the surface layer can quickly reach the user, and the back layer has a high internal loss from the viewpoint of making it difficult for unnecessary vibrations to occur in the diaphragm 10. It is preferable. For this reason, the front side (acoustic radiation direction 9 side, upper side in the figure) of the paper product 12 is composed of long fibers, and the back surface of the paper product 11 is composed of short fibers.

  As a forming material for forming the above-mentioned papermaking product, for example, natural fiber (pulp), synthetic fiber (fiber made of resin such as PET, PVA), inorganic fiber (carbon fiber, etc.) can be used. In addition, said papermaking 11 is an example of the 1st fiber entanglement body of this invention, and papermaking 12 is an example of the 2nd fiber entanglement body.

  FIG. 2B schematically shows an enlarged view of the boundary portion between the papermaking 11 and the papermaking 12 of the diaphragm shown in FIG. As illustrated, the papermaking 11 is formed of short fibers, and the papermaking 12 is formed of longer fibers. Thus, since the diaphragm 10 is formed by laminating the short fiber product 11 and the long fiber product 12, the short fiber of the paper product 11 enters the paper product 12, and the long fiber of the product 12 is a long fiber. Firmly restrained. As a result, the short fibers of the papermaking 11 that have entered the papermaking 12 are less likely to come out of the papermaking 12, and the adhesion between the papermaking 11 and the papermaking 12 is improved. That is, the paper product 11 as the first fiber entangled body and the paper product 12 as the second fiber entangled body are integrated to form the entangled region over the entire diaphragm 10. Therefore, peeling of a plurality of layers constituting the diaphragm 10 can be suppressed.

  The density of the paper product 12 is preferably larger than the density of the paper product 11. Thereby, the short fiber of the papermaking 11 can be restrained by the long fiber of the papermaking 12, and the adhesive force can be increased. Furthermore, the porosity of the paper product 12 is preferably smaller than the porosity of the paper product 11. This makes it possible to tighten the long fiber product 12 and more firmly restrain the short fiber of the paper product 11 with the long fiber of the paper product 12.

[Production method]
Next, the manufacturing method of the diaphragm 10 of an Example is demonstrated. FIG. 3 is a diagram illustrating a method for manufacturing the diaphragm 10 according to the embodiment. The diaphragm 10 is manufactured by the first to third steps.

  As shown in FIG. 3A, in the first step, the papermaking product 12 of the diaphragm 10 is formed by the papermaking apparatus 20a.

  First, the papermaking apparatus 20a will be described. The tank 21a has a substantially cylindrical shape, and is provided with a support portion 22a for arranging the papermaking net 25 therein. The tank 21a is provided with a suction port 24a near the center of the bottom, and the liquid inside the tank 21a is sucked out from the suction port 24a by the suction machine 23a. That is, the suction force in the direction of the arrow is given to the liquid inside the tank 21a by the suction device 23a.

  The papermaking net 25 is formed in advance in a shape corresponding to the shape of the diaphragm, and in this embodiment is formed in a cone shape. The papermaking net 25 has a plurality of holes formed in a net shape, for example. Of the suspension containing the forming material of the papermaking constituting the diaphragm, the forming material is deposited on the papermaking net 25, and the liquid passes through the plurality of holes and is discharged from the suction port 24a. As the papermaking net 25, for example, a metal net or punching metal can be used.

  Next, the first step will be described. First, the papermaking net 25 is disposed on the support portion 22a in the tank 21a, and the suspension 32 is put thereon, and the suction force by the suction machine 23a is given. In the first step, a suspension 32 in which long fibers are suspended is used as a material for forming the papermaking 12. The forming material contained in the suspension 32 is deposited on the screen net 25, and the other liquid is discharged from the suction port 24a. Thus, the papermaking 12 is deposited on the papermaking net 25.

  Next, the second step is performed. FIG. 3B shows the second step. In the second step, a paper making apparatus 20b different from the first step is used. The papermaking apparatus 20b basically has the same configuration as the papermaking apparatus 20a.

  In the second step, first, the suspension 31 is poured into the tank 21b. The suspension 31 is a suspension of short fibers as a material for forming the papermaking 11. Next, the papermaking net 25 on which the papermaking product 12 is deposited in the first step is taken out of the tank 21 a and immersed in the tank 21 b filled with the suspension 31. At this time, the suction machine 23b is driven to immerse the papermaking net 25 in the tank 21b while sucking the papermaking product 12 deposited on the papermaking net 25. Thus, if it does not immerse while sucking, the long fiber which comprises the papermaking 12 will disperse | distribute in the suspension liquid 31 in the tank 21b, and the shape of the papermaking 12 cannot be maintained. For this reason, suction is performed before the papermaking net 25 is disposed in the tank 21 b, and the papermaking product 12 is immersed in the tank 21 b while being adsorbed by the papermaking net 25.

  When the papermaking net 25 on which the papermaking material 12 is deposited is immersed in the tank 21b, suction by the suction machine 23b is continued and the papermaking material 11 is made. Thereby, the papermaking 11 is deposited on the papermaking 12. At this time, short fibers constituting the papermaking 11 enter the papermaking 12. Further, the density of the paper product 11 continuously sucked by the suction machine 23b gradually increases, the whole paper product is tightened, and the porosity decreases. Due to this tightening, the short fibers of the papermaking 11 are firmly restrained by the long fibers constituting the papermaking 12. Thus, the papermaking 12 and the papermaking 11 are deposited on the papermaking net 25.

  Next, the third step is performed. The third step is a step of drying and molding the laminate of the paper product 12 and the paper product 11. FIG. 3C shows the third step.

  In the third step, the papermaking net 25 on which the papermaking 12 and the papermaking 11 are deposited is pulled up from the tank 21b and disposed between the molds 50 (the upper mold 51 and the lower mold 52), and then the papermaking net 25. Is removed from the mold 50. At that time, the laminate of the paper products 11 and 12 is arranged so that the paper product 11 is on the lower die 52 side and the paper product 12 is on the upper die 51 side. Then, the mold 50 is heated and pressed to be dried and molded. Thus, the diaphragm 10 having the paper products 11 and 12 is produced.

  In this manufacturing method, since the papermaking 12 is immersed in the suspension 31 while the papermaking 11 is formed in the second step, hydrogen bonding between fibers is more likely to occur. Moreover, since the short fiber of the papermaking 11 does not lie down, but protrudes in the direction of the long fiber of the papermaking 12, it is estimated that the hydrogen bond between fibers is easy to occur. Thereby, the adhesive force of the paper products 11 and 12 increases, and the diaphragm 10 which is hard to peel can be obtained.

[Comparison with comparative example]
Next, a peeling experiment of the diaphragm of the example was performed. Specifically, the difficulty of peeling between the diaphragm of the example and the diaphragm of the comparative example was compared.

  First, a method for manufacturing a diaphragm according to a comparative example will be described with reference to FIG. In the manufacturing method of the comparative example, the paper product 11 and the paper product 12 are manufactured separately. Specifically, in the first step shown in FIG. 4A, the papermaking apparatus 40a is used to perform papermaking using the suspension 32, and the papermaking product 12 is formed on the papermaking net 45a. Simultaneously or concurrently with the first step, the second step shown in FIG. 4B is performed. That is, using the papermaking apparatus 40b, papermaking is performed using the suspension 31, and the papermaking 11 is formed on the papermaking net 45b.

  Next, the third step shown in FIG. First, the papermaking net 45b on which the paperwork 11 has been deposited in the second step is placed on the lower mold 52, and the paperwork 11 is moved onto the lower mold 52 while being sucked from a suction port (not shown). Next, similarly, the paper product 12 formed in the first step is moved onto the lower mold 52, that is, onto the paper product 11. And the upper mold | type 51 is mounted, and it heats and presses and performs drying and shaping | molding. The diaphragm thus obtained is referred to as “the diaphragm of Comparative Example 1”.

  In the experiment, a part of each of the diaphragm of Example and the diaphragm of Comparative Example 1 was cut out, and the paper products 11 and 12 were peeled off by hand. Then, it was found that the diaphragms 11 and 12 were in close contact with each other so that the diaphragm of the example was difficult to remove by hand or one of the sheets was torn when peeled off. Moreover, when the peeling surface was observed, it was confirmed that the short fiber of the papermaking 11 remains in the whole surface of the papermaking 12 of a long fiber. From this, in the diaphragm of the example, it is understood that the short fibers of the papermaking 11 enter the papermaking 12 and are firmly restrained by the long fibers of the papermaking 12.

  On the other hand, the diaphragm of Comparative Example 1 had a lower resistance when peeled than the diaphragm of the example. Moreover, when the peeling surface was observed, it turned out that the short fiber of the papermaking 11 remains only in a part of surface of the papermaking 12 of a long fiber. From this, in the diaphragm of Comparative Example 1, it is understood that the short fibers of the papermaking 11 have hardly entered the papermaking 12 and are not firmly restrained by the long fibers of the papermaking 12. .

  Thus, in the diaphragm of an Example, since the short fiber of the papermaking 11 is restrained firmly by the long fiber of the papermaking 12, it turns out that two papermakings closely_contact | adhere and can suppress peeling.

[Concrete example]
Hereinafter, specific examples of the diaphragm according to the embodiment will be described. FIG. 5 shows the characteristics of Specific Examples 1 and 2 and Comparative Example 2 of the diaphragm according to the example. Specific examples 1 and 2 are diaphragms composed of two layers of a short fiber layer and a long fiber layer, which balance the internal loss and Young's modulus while integrating the two layers by the method of the example. . Comparative Example 2 is a diaphragm composed of only a single layer. In addition, the comparative example 2 is different from the comparative example 1 mentioned in the column of the manufacturing method.

  In Example 1, the papermaking product 12 on the acoustic radiation side (front side) of the speaker device was made with wood pulp fiber NBKP having a beating degree of 20 ° SR, which is a long fiber. Further, the paper product 11 on the opposite side (back side) of the acoustic emission side of the speaker device is made of wood pulp fiber NBKP (length: about 2 to about 5 mm, thickness: about 0) with a beating degree of 20 ° SR, which is a long fiber. 0.03 mm to 0.07 mm) and short fibers (hollow plant fibers, length: about 0.7 mm to about 1.3 mm, thickness: about 0.04 mm to about 0.08 mm). The wood pulp fiber NBKP with a beating degree of 20 ° SR constituting the papermaking 11 is 80% by weight, and the hollow fiber is 20% by weight.

  In Example 2, the papermaking product 12 on the acoustic radiation side (front side) of the speaker device was made with wood pulp fiber NBKP having a beating degree of 20 ° SR, which is a long fiber. Further, the paper product 11 on the opposite side (back side) of the acoustic emission side of the speaker device is made of wood pulp fiber NBKP (length: about 2 to about 5 mm, thickness: about 0) with a beating degree of 20 ° SR, which is a long fiber. 0.03 mm to 0.07 mm), hollow fibers that are short fibers (hollow plant fibers, length: about 0.7 mm to about 1.3 mm, thickness: about 0.04 mm to about 0.08 mm), short fibers A certain polyester fiber (length: about 0.9 mm to about 3 mm, thickness: about 0.01 mm to about 0.05 mm) was used. The pulp product NBKP with a beating degree of 20 ° SR constituting the papermaking 11 is 70% by weight, the hollow fiber is 20% by weight, and the polyester fiber is 10% by weight.

  In Comparative Example 2, a single paper product was made with wood pulp fiber NBKP having a beating degree of 20 ° SR.

  The diaphragms of Comparative Example 2 and Specific Examples 1 and 2 were formed to have substantially the same thickness. In Examples 1 and 2, the wood pulp fiber, which is a long fiber of Comparative Example 2, is replaced with a hollow fiber that is a short fiber or a polyester fiber that is a short fiber.

  From the table shown in FIG.

  By using a hollow fiber or a polyester fiber as a relatively short fiber having a relatively large internal loss, the internal loss of the diaphragm is improved over the internal loss of the diaphragm of Comparative Example 2, It can be seen that the decrease in Young's modulus is suppressed as much as possible, and the balance between internal loss and Young's modulus is adjusted.

  Moreover, about the diaphragm of these specific examples, the part was cut off and the papermakings 11 and 12 were peeled by hand. Then, it was found that the diaphragms of specific examples 1 and 2 were difficult to peel off by hand, or the paper products 11 and 12 were in close contact with each other so that any paper product was torn when peeled off. . Moreover, when the peeling surface was observed, it was confirmed that the short fiber of the papermaking 11 remains in the whole surface of the papermaking 12 of a long fiber.

[Modification]
In said Example, the papermaking 11 is comprised with the short fiber, and the papermaking 12 is comprised with the long fiber. Alternatively, the paper product 11 may be composed of soft fibers, that is, fibers having low rigidity or large internal loss, and the paper product 12 may be composed of rigid fibers, that is, fibers having high rigidity or high Young's modulus. Good.

  Moreover, the papermaking 11 may be comprised with a thin fiber, and the papermaking 12 may be comprised with a thick fiber. Furthermore, the paper product 11 is composed of fibers with a low beating degree, that is, fibers with a small surface area, and the paper product 12 is made of fibers with a high beating degree, that is, fibers with a large surface area, fibrillated (a state where many branches are branched) You may comprise with the fiber which did.

  As described above, the embodiments of the present invention have been described in detail with reference to the drawings. However, the specific configuration is not limited to these embodiments, and the design can be changed without departing from the scope of the present invention. Is included in the present invention. The embodiments described in the above drawings can be combined with each other as long as there is no particular contradiction or problem in the purpose, configuration, or the like. Moreover, the description content of each figure can become independent embodiment, respectively, and embodiment of this invention is not limited to one embodiment which combined each figure.

10 Diaphragm 11, 12 Papermaking 20a, 20b, 40a, 40b Papermaking equipment 21a, 21b, 41a, 41b Tank 23a, 23b, 43a, 43b Suction machine 25, 45a, 45b Papermaking net 31, 32 Suspension 50 Gold Type

Claims (9)

A first fiber entangled body and a second fiber entangled body,
The loudspeaker diaphragm, wherein the entangled body of the first fibers and the entangled body of the second fibers are integrated.   The speaker diaphragm according to claim 1, wherein a length of the first fiber is smaller than a length of the second fiber.   The speaker diaphragm according to claim 2, further comprising an entangled region of the first fiber and the second fiber.   The speaker diaphragm according to claim 3, wherein the density of the second entangled body is higher than the density of the first entangled body.   The speaker diaphragm according to claim 4, wherein a porosity of the entangled body of the second fibers is smaller than a porosity of the entangled body of the first fibers.   The speaker diaphragm according to claim 1, wherein the first fiber has lower rigidity than the second fiber.   The speaker diaphragm according to claim 1, wherein the first fiber is thinner than the second fiber.   The speaker diaphragm according to claim 1, wherein the first fiber has a lower beating degree than the second fiber.   4. The speaker diaphragm according to claim 3, wherein, in the entangled region, the first fiber protrudes from the entangled body of the first fiber toward the entangled body of the second fiber.

Images