JPS6123920B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for manufacturing a speaker diaphragm that includes a cone-shaped diaphragm body and a diaphragm edge that is continuous to the outer periphery of the diaphragm body. Conventionally, this type of manufacturing method uses a paper mesh having the same shape as the diaphragm, and reduces pressure on the back side of the paper mesh to adhere pulp slurry to the front surface of the paper mesh, and then produces one or more diaphragms. A method is known in which paper is made by taking at most several pieces, but this is extremely unsuitable for mass production. Moreover, since the paper mesh has a truncated cone-shaped inclined part (i.e., a cone-shaped part) corresponding to the vibrating part with a large thickness, this inclined part and other parts (i.e., the diaphragm edge part)
The disadvantage is that paper cannot be made in one piece. Another method is to bond uniform continuous sheets together in a conical shape, but this increases the thickness at the bonded surface, which is disadvantageous for performance, etc., and requires the edge portion to be attached separately. Therefore, the bonding work itself is troublesome. Furthermore, for example, according to the method disclosed in Japanese Patent Publication No. 41-14044, continuous fiber layers are made into wet paper using a rotary Fourdrinier machine, which is dehydrated under reduced pressure to form a core layer, and then the paper is made into a core layer. Paper stock is poured onto the upper surface of the core layer through the opening of a partial paper making device to form a partially double-layered fiber layer for a diaphragm. However, since the pulp slurry is oriented in this guide direction when paper is made using a Fourdrinier paper machine, the physical constants of the paper are different in the machine direction and the machine direction. Moreover, when forming the skin layer by pouring paper stock onto the core layer, which is made by dehydrating paper-made wet paper to a moisture content of about 70%, the paper stock is in the form of a slurry, so it is laminated onto the underlying core layer. The disadvantage is that the paper gets mixed up without being mixed together, and the paper tends to tear. Furthermore, since it is necessary to dehydrate the paper after forming the core layer and after forming the skin layer, the speed of papermaking becomes slow. In order to correct such deficiencies, the applicant
We have already proposed a completely new method on April 28, 2017.
In this method (hereinafter referred to as the "first application method"), a sheet-like back layer is continuously formed by a first cylinder paper making device equipped with a first rotating drum provided with a first paper making mesh. a step of making paper; a second paper-making net having at least a predetermined pattern corresponding to a planar development shape of a cone-shaped diaphragm body of a speaker diaphragm to be manufactured;
A step of continuously making paper with a surface layer having at least a pattern layer corresponding to the predetermined pattern by a second cylinder paper making machine which is equipped with a rotating drum and is separate from the first cylinder paper machine. , a step of laminating the back layer and the surface layer in a wet paper state and pressing them to obtain a laminated paper; a step of press-molding the pattern layer portion of the laminated paper to form a cone shape; A method of manufacturing a diaphragm for a speaker, comprising the steps of: forming a diaphragm body; and forming a diaphragm edge by a part of a back layer continuous to the outer periphery of the diaphragm body. It is something. By this method, diaphragms with low density, homogeneity, high rigidity, and high strength can be mass-produced with good workability, and high-speed paper making is possible. A diaphragm having a cone-shaped diaphragm main body in a cone-shaped state and a diaphragm edge consisting of a back layer can be manufactured by a simple molding process. However, although the method of this prior application has a remarkable effect, it has been found that there is still room for improvement. In other words, the two layers are intertwined during the lamination process, thereby obtaining laminated paper, but since the material is originally paper, 3 layers are intertwined during the next press forming process.
The elongation is only about 7%, making it difficult to manufacture diaphragms of various shapes. Therefore, only relatively simple shapes, small diameter, and shallow types can be manufactured. The present invention has been invented in order to further improve the above-described features of the prior application method, and includes: a first cylinder paper making method comprising a first rotary drum provided with a first paper making mesh; A step of continuously paper-making a sheet-like back layer using an apparatus; a second paper-making net having at least a predetermined pattern corresponding to the planar development shape of a cone-shaped diaphragm body of a speaker diaphragm to be manufactured; The second
A step of continuously making paper with a surface layer having at least a pattern layer corresponding to the predetermined pattern by a second cylinder paper making machine which is equipped with a rotating drum and is separate from the first cylinder paper machine. , a step of laminating the back layer and the front layer in a wet paper state and pressing them to obtain a laminated paper; a step of changing the feeding speed of the laminated paper at a certain point to change the changed portion; a step of creasing the laminated paper, press-molding the pattern layer portion of the laminated paper to form a cone-shaped diaphragm body, and a back surface continuous to the outer periphery of the diaphragm body; The method of manufacturing a speaker diaphragm includes the following steps: forming a diaphragm edge by a part of the layer. By this method, not only can all the effects of the above-mentioned method of the prior application be achieved, but also a diaphragm with a large diameter and a complicated shape can be easily manufactured by increasing the elongation rate of the laminated paper. In a further development of the present invention, the first
A non-directional back layer and a surface layer are each made at the same speed using a second cylinder paper making device, and these layers are press laminated while still in the wet paper state to produce a laminated paper for a diaphragm. After this is moistened, it is press-molded into the shape of a diaphragm. In this case, in order to perform non-directional paper making, a cylinder paper machine equipped with a rotating drum with a paper making net is used, and the water level difference between the pulp slurry side and the inside of the rotating drum is used, or the water level inside the rotating drum is used. Either actively reduce the pressure to make the pulp slurry adhere to the outer peripheral surface of the rotating drum, and increase the adhesion speed (papermaking speed) relative to the rotational speed of the rotating drum, or stir the pulp slurry side to make the slurry adhere to the outer peripheral surface of the rotating drum. is not oriented in the direction of rotation of the rotating drum. Furthermore, if the wet paper is laminated in its state as described above, both layers will be sufficiently intertwined at the interface without tearing, resulting in a strong and high-quality laminated paper. In addition, the state of this wet paper is preferably one in which the ratio of water to pulp is 5:1 to 3:1 in terms of moisture content, which means that the paper is in a swollen state. say. In this case, if the moisture content is out of the above range and there is too much water, the pattern of the surface layer will be disturbed and it will be difficult to maintain, and if there is too little water, the intertwining of both layers will be insufficient and the lamination after lamination will be difficult to maintain. Strength decreases. Furthermore, after lamination, for example, the laminated paper is guided to a rotating drum for drying while being fed by a belt, but at this time, the rotational speed of the drum is made lower than that of the belt, and the laminated paper is fed in the area near the drum and the belt. The laminated paper is wrinkled by slowing down and then guided over the circumference of the drying drum. As a result, wrinkles are forced into the laminated paper in the wet paper state, and during the next press forming,
In addition to elongation from the entangled state of fibers,
The elongation of the wrinkled portions also contributes to the elongation of the entire paper, and therefore a laminated paper with a high elongation rate can be obtained. Next, embodiments of the present invention will be described with reference to the drawings. 1 to 8 show a first embodiment of the present invention. First, referring to FIG. 1, the configuration of a cylinder paper making apparatus 1 for making paper for a core layer as a back layer and a skin layer as a surface layer will be explained. This papermaking apparatus comprises a rotating drum 3 with a papermaking screen 2, which is partially immersed in pulp slurry 5 in a container 4. Also rotating drum 3
A suction box 6 for depressurization is fixedly disposed at a position close to the liquid level of the pulp slurry 5 on the right side of the box. Although the illustration is simplified, this suction box actually extends to the center of the rotating drum 3, and by reducing the pressure with a vacuum pump or the like through this center, the suction box extends in the radial direction toward the center of the rotating drum 3. It is constructed so that a suction force is generated. Next, the paper making method using this paper making apparatus 1 will be explained. By rotating the rotary drum 3 in a clockwise direction 8 while applying suction force by the suction box 6, the outer periphery of the paper making net 2 in the suction box 6 portion is The pulp slurry 5 near the liquid surface is sucked onto the surface, and the pulp 9 is adhered to a predetermined thickness as shown in the figure. In such a state, the pulp 9 adheres to the papermaking net 2 in such a way that it bites into it, so that it is guided in the rotational direction of the rotary drum 3 without detaching from the papermaking net. Then, since the pulp 9 sequentially adheres to the paper mesh near the liquid surface of the pulp slurry 5, as shown in the figure, the pulp 9 is continuously attached to the circumferential surface of the rotating drum 3 in the pulp slurry 5. You will be guided. As a result of the suction and adhesion of the pulp 9, moisture in the pulp slurry 5 is absorbed into the papermaking net 2.
The white water 10 is taken into the rotating drum 3 and accumulated in the rotating drum 3 as white water 10. A certain height difference or water level difference h exists between the liquid level of the white water 10 and the liquid level of the pulp slurry 5. Therefore, even if this water level difference is used, the pulp above the liquid level of the white water 10, especially near the liquid level of the pulp slurry 5, can be attached to the papermaking net 2 in the same way as in the above case, so it is not always possible to There is no need to use the shock box 6 to perform suction. However, it is more desirable to actively perform vacuum suction using the suction box 6, since the pulp 9 is more likely to adhere to the pulp 9 and the adhering state becomes uniform. When attaching the pulp 9 in this way,
By increasing the paper making speed (i.e., the adhesion speed of the pulp 9) with respect to the rotation speed of the rotating drum 3,
Since the pulp slurry 5 around the rotary drum 3 does not follow the rotation of the rotary drum 3 and flow, the fibers are not oriented in the rotational direction of the rotary drum 3, and uniform paper can be made. In this case, if the pulp slurry 5 is stirred by an appropriate means, the orientation of the fibers can be better prevented, but if this stirring is performed, the fibers can be blended sufficiently without increasing the papermaking speed as described above. can be reduced to The pulp 9 that comes out of the liquid surface of the pulp slurry 5 while being guided around the rotating drum 3 is guided onto a belt-shaped blanket 12 as a wet paper 11, where a predetermined amount of moisture from the wet paper 11 is removed. do. blanket 12
is moved in the direction of arrow 14 by the guide roller 13, so the wet paper 11 from the rotating drum 3 is transferred to the blanket 1.
2 in the direction of arrow 14. Two cylinder paper making machines shown in Fig. 1 are used as shown in Fig. 2, and in one paper making machine 1a, a kraft pulp slurry 5a is stored in a container to form a wet paper paper that becomes a core layer (back layer). In the other paper making device 1b, a Japanese paper material slurry 5b such as gampi, mitsumata, etc. is stored in a container, and wet papers 11b and 22, which will become a skin layer (surface layer), are made into paper in a predetermined pattern. . The kraft pulp for the core layer is flexible, whereas the Japanese paper material for the skin layer has a low density ρ, a high Young's modulus E, and a high longitudinal wave propagation velocity √ because it is used for the vibrating part. It is. The wet paper that becomes the skin layer is
As will be explained in detail later, since a large number of substantially circular pattern layers 11b are regularly arranged as shown in FIG. The paper making net is also constructed to have mesh portions with the same pattern. On the other hand, since the wet paper web 11a serving as the core layer consists of a single continuous layer, the paper making device 1a
The paper-making mesh of the rotating drum consists of a nearly uniform mesh throughout. Next, in FIG. 2, wet paper sheets 11a and 11
b, 22 between a pair of rolls 15, 16,
It is pressed between these two rolls and laminated. At this time, the wet papers 11a, 11b, 22 have a predetermined moisture content, for example, 80%,
When pressed, both wet paper papers 11a, 11b, and 22 intertwine well with each other, and can be taken out as a laminated paper 17 having desired lamination strength. Therefore, sufficient adhesive strength can be obtained without using an adhesive as in the past. The laminated paper 17 is then guided via guide rollers 18 onto a rotating drying drum 19, where it is subsequently thermally dried. After this drying, the paper is sequentially wound onto a roll 20 and stored as a dry laminated paper for a diaphragm. The important thing at this time is the third
As clearly shown in the figure, the laminated paper 17 guided in the direction of the arrow 26 by the blanket belt 25 on the guide roller 18 is guided to a rotating drum 19 having a relatively low rotational speed and placed close to the end of the belt 25. It is. For example, the feed speed of the belt 25 is 8
m/min, and the rotation speed of the rotating drum 19 is 7 m/min.
If the diameter is 3 to 4 m, the speed of the laminated paper 17 decreases in the vicinity of the belt 25 and the drum 19, so that the folds 27 on the laminated paper 17 are formed relatively regularly, that is, in the feeding direction. They will be parallel to each other almost at right angles. Therefore, the laminated paper 17 is dried on the circumferential surface of the rotating drum 19 while having wrinkles 27 almost uniformly, and is wound onto the roll 20 as it is. The wrinkles 27 are shown in an exaggerated manner in FIG. 3, and are omitted from FIGS. 4 to 6 for ease of understanding. The laminated paper 17 has the shape and structure shown in FIGS. 4 and 5. That is, the core layer 11a is composed of a flexible continuous layer made of kraft pulp. Further, the skin layer includes a substantially circular pattern layer 11b made of Japanese paper material and having a circular cutout 21 approximately in the center, and these circular pattern layers 11.
The circular pattern layer 11b is made of the same material as the Japanese paper material layer 22, which is made at the same time as the Japanese paper layer 11b, and surrounds the circular pattern layer 11b through a ring-shaped cutout. This material layer maintains the pattern of the circular pattern layer 11b in a good condition without disturbing it. Note that the core layer 11a is exposed in a ring shape between the Japanese paper material layer 22 and the circular pattern layer 11b through the ring-shaped cutout,
This ring-shaped portion becomes a diaphragm edge, which will be described later. Next, the laminated paper 17 is rewound from the roll 20 and soaked in water to return it to a wet paper state again. This state is shown in an enlarged view in FIG. 6, and this is further pressed into a mold at 150° C. to produce a cone-shaped diaphragm 23 as shown in FIG. At this time, the circular pattern layer 11b portion of the laminated paper 17 is press-molded into a cone-shaped diaphragm main body, and the ring-shaped portion continuous to the outer periphery of the circular pattern layer 11b portion is formed as shown in the figure. The diaphragm edge 24 is press-molded at the same time, and the periphery thereof is cut to form individual diaphragms 23. In this press forming, the laminated paper 17 shown in FIG. 6 is in the state of wet paper, so it can be stretched. However, as the laminated paper 17 is still wrinkled due to the process shown in FIG. Even if it is set to 23, an elongation rate of about 15% can be obtained. As a result, a tweeter with a diameter of 25 mm can be manufactured as a treble speaker, but this is deep (that is, deep) and generally difficult to press mold, but according to this example, the paper is damaged. It is possible to mold the product without any process. Note that the press forming of the diaphragm 23 is not limited to the above-mentioned method. First, the laminated paper for the diaphragm is cut out into circular shapes in the state shown in FIG. 4, separated into the shapes shown in FIG. After returning to paper, press molding may be performed in the same manner as described above. As is clear from the above explanation, the method according to the present embodiment involves wrinkles 27 in the laminated paper 17 obtained by laminating both paper layers, and then press-molding in the state of wet paper, thereby forming fibers. Since each diaphragm is formed by utilizing the intertwining and elongation from the wrinkled state, it is not possible to manufacture diaphragms one by one or by pasting them as in the past. It is possible to mass-produce low-density, high-rigidity diaphragms with good workability, and it is also possible to easily manufacture deep-shaped diaphragms that are difficult to mold. In addition, during paper making, the pressure inside the rotating drum 3 is reduced to make the paper making speed higher than the rotating speed of the rotating drum 3, so a skin layer and a core layer made of non-directional fibers can be formed, and the physical constants of the diaphragm can be made uniform. In addition, since the laminated paper 17 is formed as a wet paper, the fiber entanglement between the substantially non-directional back layer and surface layer is used to form the paper into a certain shape. Can be laminated while retaining
A homogeneous and strong diaphragm can be reliably obtained. Moreover, after papermaking, the wet paper is laminated without dehydration, and the drying process using the rotating drum (drying) 19 is only required once, which improves the overall working speed and enables high-speed papermaking, increasing efficiency. becomes significantly better. Next, a specific example of this embodiment will be explained. As mentioned above, the speaker diaphragm has a high Young's modulus, a low density, and a longitudinal wave propagation velocity √
Although ρ is required to be large, the physical constants of the diaphragm according to this embodiment using Gampi for the skin layer and the diaphragm using conventional general paper are shown in the table below.

[Table] From the results, it can be seen that the diaphragm according to this example has a large Young's modulus and a better √ than the conventional example, and is therefore very excellent. The skin layer (manufactured by Ganpi) of the diaphragm according to this example had a beating degree of 28°SR, and the beating degree of the core layer (made by craft pulp NUKP) was 9°SR. Further, the frequency characteristics of the diaphragm according to this specific example of this embodiment and the diaphragm of the conventional example described above are shown in comparison in FIG. According to this, it can be seen that the sound pressure level (curve a) of the diaphragm according to this specific example is higher in most regions than that of the conventional example (broken line b), and has excellent frequency characteristics. Next, a second embodiment of the present invention will be described with reference to FIG. This embodiment differs from the first embodiment only in the method of wrinkling the laminated paper, so common parts will be given common reference numerals and their explanation will be omitted. That is, the laminating paper 17 that has come out from between the laminating rolls 15 and 16 is guided on the circumferential surface of the upper roll 15, and is guided along a wedge-shaped guide plate 30 called a doctor while being guided by a guide roller 31.
and a blanket belt (not shown) driven by the rotating drum 19 and the touch roller 32. In this case, if the rotational speed of the rotary drum 19 is made smaller than the rotational speed of the rolls 15 and 16 as shown in the table below, wrinkles 27 will appear in the laminate paper 17 at the point of the guide plate 30, and the wrinkled laminate will The paper is guided along the rotating drum 19 and dried in the same manner as described above.

[Table] From this result, it can be seen that the elongation rate of the laminated paper generally improves as the rotational speed of the rotating drum 19 is decreased.
It can also be seen that by changing the ratio of the rotational speeds of 5 and 16, the elongation rate of the paper can be freely selected and various types of diaphragms can be manufactured. Generally speaking, an elongation rate of about 15% is sufficient even for deep speakers, and it is understood that this example can reliably achieve this. Although the present invention has been described above based on examples thereof, it will be understood that the present invention is not limited to these examples and can be further modified. For example, the wet paper papers 11a, 11b, 22 can be made of other materials, and the Japanese paper material layer 22 in FIGS. 4 and 5 does not necessarily have to exist, and the skin layers 11b, 22 and the core layer 11a
You may also change the shape, size, etc. Further, in the above embodiment, the pulp 9 was attached along the lower side of the rotating drum 3 during paper making, but the attached pulp was removed by rotating the rotating drum 3 in the opposite direction (i.e., counterclockwise). The pulp slurry 5 may be guided along the upper outer peripheral surface and placed on the blanket 12 as it is without being guided through the pulp slurry 5. In this case, the wet paper is guided to the bottom surface of the blanket 12 instead of the top surface, and the wet paper is guided to the roll presses 15 and 16 while being attached to the bottom surface by utilizing the adhesive force of the wet paper to the blanket. Although it is also possible to do this, it is necessary to arrange couch rolls on a rotating drum and to sandwich the blanket and wet paper between them to form a unit. Further, when press forming, the laminated paper was dried in the above-mentioned embodiment, but the laminated paper in a wet paper state after passing between the rolls 15 and 16 may be press-formed as it is. Further, instead of the drying rotary drum 19, a simple rotary drum may be used, and the wrinkled laminated paper may be guided in the form of a wet paper on this rotary drum, and then immediately sent to the press molding process. Furthermore, the method of wrinkling the laminated paper can be changed in various ways. For example, as shown in FIG.
Even if the driving speeds of the blanket belts 35 and 36 guided by the belt 34 are made different and the speed of the belt 36 is made smaller than that of the belt 35, wrinkles 27 do not occur on the laminated paper 17.
can be brought together effectively. Note that the present invention is also applicable to other types of diaphragms with large aperture ratios (large diameter deep type, dome type, etc.). As described above, the present invention involves laminating a substantially non-directional back layer and a surface layer, each of which is continuously made into paper by the first and second cylinder paper making devices, in the state of a wet paper. Because we obtain paper, we can press-form this laminated paper to make individual diaphragms, and therefore we can mass-produce low-density, high-rigidity diaphragms with good workability.
Furthermore, by utilizing the intertwining of fibers between the substantially non-directional back layer and surface layer, laminated paper can be formed while maintaining a certain shape as paper, thus creating a homogeneous and strong diaphragm. can be manufactured. Furthermore, since it is possible to laminate the paper in its wet paper state without requiring dehydration after papermaking, the overall working speed can be improved and high-speed papermaking is therefore possible. In addition, by providing the paper making mesh of the second cylinder paper making device with a predetermined pattern corresponding to the planar development shape of the cone-shaped diaphragm body of the speaker diaphragm to be manufactured, the above-mentioned predetermined pattern can be accommodated. A cone-shaped diaphragm main body is formed by press-molding the pattern layer portion of the laminated paper, and a back layer continuous to the outer periphery of the diaphragm main body. A vibrating edge is formed by a part of the Therefore, a speaker diaphragm comprising a cone-shaped diaphragm main body with a laminated surface layer and a back layer, and a diaphragm edge made of the back layer can be manufactured by a simple molding process. However, since the feed speed is changed at a certain point after lamination to cause wrinkles in the laminated paper, during the next forming process, not only the elongation due to the entanglement of paper fibers but also the wrinkles themselves. Elongation also works, and the overall elongation rate is greatly improved. Therefore, even a relatively complicated diaphragm with a large drawing ratio can be manufactured easily.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and FIG. 1 is a sectional view of a cylinder paper machine according to the first embodiment, and FIG. 2 is a process diagram of a diaphragm manufacturing plant using this paper machine. , FIG. 3 is a schematic diagram of a mechanism for creasing laminated paper in this plant, FIG. 4 is a plan view of laminated paper laminated in this plant, and FIG. 5 is a sectional view taken along the line - in FIG. 4. Fig. 6 is a partially enlarged view of Fig. 5, Fig. 7 is a cross-sectional view of a diaphragm obtained by press forming from the state shown in Fig. 6, and Fig. 8 shows the sound pressure level of a speaker incorporating the diaphragm. Frequency characteristics, Figure 9 is the second
FIG. 10 is a schematic view of the main parts of a diaphragm manufacturing plant according to the embodiment described above, and FIG. 10 shows a modification of the above-described embodiment, and is a schematic diagram of a mechanism for creasing laminated paper. In addition, in the symbols used in the drawings, 1 is a cylinder paper machine, 2 is a paper making net, 5 is a pulp slurry, 6 is a suction box, 9 is a pulp, and 11 is a pulp slurry.
15 and 16 are wet paper, 15 and 16 are rolls, 17 is laminated paper, 19 is a rotating drum (for drying), 22 is a Japanese paper material layer, 23 is a diaphragm, 24 is a diaphragm edge, 2
5, 35, 36 are belts, 27 is a wrinkle, 30 is a guide plate, 1a, 1b is a cylinder paper machine, 5a is a kraft pulp slurry, 5b is a Japanese paper material slurry, 1
1a is a core layer (back layer), and 11b is a circular pattern layer.

Claims (1)

[Claims] 1. A method for manufacturing a speaker diaphragm comprising a cone-shaped diaphragm body and a diaphragm edge continuous to the outer periphery of the diaphragm body, comprising: A step of continuously paper-making a sheet-like back layer by a first cylinder paper-making device equipped with a first rotating drum provided with a cone-shaped diaphragm body of a speaker diaphragm to be manufactured. A second paper-making net having at least a predetermined pattern corresponding to a planar developed shape is provided.
A step of continuously making paper with a surface layer having at least a pattern layer corresponding to the predetermined pattern by a second cylinder paper making machine which is equipped with a rotating drum and is separate from the first cylinder paper machine. , a step of laminating the back layer and the front layer in a wet paper state and pressing them to obtain a laminated paper; a step of changing the feeding speed of the laminated paper at a certain point to change the changed portion; a step of creasing the laminated paper, press-molding the pattern layer portion of the laminated paper to form a cone-shaped diaphragm body, and a back surface continuous to the outer periphery of the diaphragm body; A method for manufacturing a diaphragm for a speaker, comprising the steps of: forming a diaphragm edge by a part of the layer.