JPS6359320B2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a speaker diaphragm and a method for manufacturing the same, and in particular to a diaphragm with a sandwich structure in which a core material is lightweight and has high rigidity, and skin materials are bonded to the front and back sides of the core material. and its manufacturing method.

Conventional structure and its problems In general, from the material standpoint, a speaker diaphragm should be lightweight, have a large modulus of longitudinal elasticity, and have a large internal loss. - It is appropriate to make the radiation surface flat in order to obtain frequency characteristics.

In recent years, in order to achieve the above objectives, materials with high longitudinal elastic modulus (aluminum alloy,
A skin material made of carbon graphite, mica, etc. is used as a speaker diaphragm.

The core material of the honeycomb structure (hereinafter referred to as honeycomb core) is manufactured by the following method. First, as shown in FIG. 1, adhesive 2 is applied alternately at regular intervals between thin sheets 1 serving as core materials, and these are stacked and bonded. Next, cut the glued sheets to a certain width, stretch them in the stacked direction, and make a second sheet.
Make a honeycomb core as shown in the figure. A speaker diaphragm is completed by bonding skin materials to the front and back surfaces and processing them into a predetermined shape. The honeycomb core diaphragm made in this way has the characteristics of being light and having high rigidity, but it has the following drawbacks.

(1) It requires many manufacturing steps and has a low yield, resulting in high costs.

(2) Due to the structure of the core material, honeycomb cores have high bending rigidity in the X direction in Figure 2.
When used as a diaphragm, the rigidity has a directionality, such as being small in the Y direction of the figure.
The nodes become elliptical and difficult to drive.

(3) If the honeycomb core is made of metal, high peaks will occur in the sound pressure-frequency characteristics in the divided vibration range. (4) By making the cross-sectional shape of the diaphragm tapered with a thinner periphery and a thicker driving part. Although it has the effect of increasing the rigidity of the diaphragm and lowering the resonance sharpness Q, it is extremely difficult to process a honeycomb core into a tapered shape due to its manufacturing method.

On the other hand, recently, instead of the above-mentioned honeycomb core, a core material formed by molding a plastic film as shown in FIG. 3 has been proposed. Third
In the figure, 4 is a core material, 4a and 4b are peaks of the core material, 3 and 3' are skin materials, and 3a is a skin material surrounded by one cell. This core material 4 has triangular peaks 4a and 4b extending radially from the center, and has high rigidity in the radial direction. However, in the circumferential direction, the ridges 4a and 4b are not continuous at the top of the ridges, so the rigidity is low, and it also has the disadvantage that it tends to generate asymmetric mode vibrations as shown in Figure 4, causing unevenness in the directivity characteristics. There is.

In addition, the skin material is supported by the peaks 4a and 4b, and since the area of the skin material 3a in the shaded area surrounded by them is large, this skin material 3a becomes a kind of vibration membrane, and its resonance frequency increases. If it is within the reproduction band of the speaker, it resonates with the diaphragm, which has the disadvantage of producing unpleasant abnormal sound.

OBJECTS OF THE INVENTION The present invention provides a speaker diaphragm with a sanderch structure that solves the problems of the speaker diaphragm using a honeycomb core and the speaker diaphragm using a plastic core material, and a method for manufacturing the same.

Structure of the Invention The present invention has a large number of frame-shaped protrusions arranged continuously in the radial direction on one surface, and linear protrusions arranged in the radial direction at the bottom of each of the frame-shaped protrusions on the other surface. A core material with a section is molded from plastic,
Skin materials are arranged on both the front and back sides of this core material, and the skin materials are adhered to the frame-shaped protrusion and the linear protrusion. With this structure, the above-mentioned conventional problems can be solved at once. It can be solved.

DESCRIPTION OF EMBODIMENTS FIG. 5 is a perspective view showing a part of a diaphragm in an embodiment of the present invention. In FIG. 5, 5 is a core material, and 3 and 3' are skin materials adhered to both the front and back sides of the core material. A large number of recesses, usually called cells 5a, are provided on the front side of the core material 5.
Each cell 5a is surrounded by a rectangular frame-shaped protrusion 5b, and each frame-shaped protrusion 5b is continuously formed radially from the center of the diaphragm. On the other hand, on the back side of the core material 5, a linear protrusion 5c is formed linearly in the radial direction as a portion to which the skin material 3' on the back side is bonded to the bottom of each cell 5a. The core material 5 of this example is manufactured as follows.

First, a recess 6 having a rectangular protrusion 6a shown in FIG. 6 is created. Further, as shown in FIG. 7, in order to form a part to be bonded to the skin material 3' on the back side, a convex mold 7 having plugs 7a radiating and linear from the center corresponding to the cells of the concave mold 6 is created. . FIG. 8a is a radial cross-sectional view showing a state in which the concavo-convex molds 6 and 7 are set on the top and bottom of the film 8. When the film 8 is heated and pressed, it is formed as shown in FIG. 8b, and the core material 5 as shown in FIG. 5 is obtained.

As described above, according to this embodiment, the plastic film can be formed using a press mold, so that the number of man-hours can be reduced compared to the conventional diaphragm using a honeycomb core. Furthermore, since the cell pattern of the core material can be made radial, the nodes of the vibration mode of the diaphragm are circular, making it easy to drive the nodes. Further, since the frame-shaped protruding portion 5b also has ridges in the circumferential direction, the rigidity is increased and resistance to asymmetric vibrations as shown in FIG. 4 is increased. In addition, the skin material of the diaphragm using the conventional plastic core is OA shown in Fig. 9.
It was supported by the OB, but in this example, the shaded part
Since ABCD can be made smaller than before, its resonant frequency becomes higher, and it has the advantage of being able to drive the so-called cell noise, where the skin material resonates, out of the reproduction band.

FIG. 10 is a perspective view showing a part of another embodiment of the present invention. This core material 9 is obtained by gradually changing the thickness of the core material 5 in the radial direction of the core material 5 shown in FIG. This core material 9 can be obtained by performing press molding similar to that shown in FIGS. 8a and 8b using a plug mold 10 in which the plug 10a is tapered as shown in FIG.

As described above, in addition to the features of the previous embodiments, this embodiment has the great feature that it is possible to easily obtain a tapered core material, which is difficult to obtain with a honeycomb core.

Furthermore, with conventional honeycomb cores, there is a problem that the driving part becomes elliptical due to the directionality of the rigidity, but in the present invention, by forming the cells in a radial pattern, the nodes of the vibration mode become circular, as shown in Fig. 12. Since the conical coupling cone 11 can be used,
The coupling cone can be easily processed and inexpensive speaker units can be manufactured. In FIG. 12, 12 is an edge, 13 is a diaphragm, 14 is a frame, 15 is a damper, 16 is a bobbin, 17 is a voice coil, 18 is a plate, 19 is a magnet, and 20 is a yoke.

Further, in the above two embodiments, the shape of the cell is a quadrilateral, but it may be other polygonal or elliptical shapes, and any shape as long as it is a frame shape can be applied.

Effects of the Invention As described above, according to the present invention, by configuring the cells surrounded by the frame-shaped protrusions radially and continuously from the center of the drive plate, the rigidity in the radial direction can be increased, and the asymmetric vibration Since there is no dip in the characteristics.

Furthermore, since the cells of the core material become smaller, the resonance of the skin material can be pushed to a higher frequency than the reproduction band of the speaker, and fatal defects such as chattering of the skin material can be eliminated during reproduction.

In addition, in terms of the manufacturing method, conventional honeycomb core manufacturing methods required more than ten steps, but in the case of the present invention, only three steps are required if the plastic film is press-molded, resulting in a significant cost reduction. have.

In addition, since it is possible to use a material with a higher internal loss than metal for the core material, it is possible to suppress the peak in the divided vibration range, extending the usable band, and reducing the distortion accompanying the peak. can be reduced.

Furthermore, by changing the cross-sectional shape of one of the molds, it is possible to obtain a tapered shape that is optimal for a diaphragm.

[Brief explanation of drawings]

Figure 1 is a cross-sectional view for explaining the manufacturing method of a honeycomb core used in a conventional diaphragm.
The figure is a plan view of the honeycomb core, Figure 3 is a cutaway perspective view of the main part of a speaker diaphragm using a conventional mountain-shaped core material, and Figure 4 is a diagram showing the asymmetric mode of the diaphragm of Figure 3. FIG. 5 is a perspective view showing a main part of the speaker diaphragm according to the first embodiment of the present invention; FIG. Figure 7 is a perspective view showing a part of the convex mold for molding the core material of the first embodiment, Figures 8a and b are diagrams showing the process of molding the core material of the first embodiment, and Figure 9. 10 is a diagram comparing the sizes of the cell of the present invention and a conventional cell, FIG. 10 is a perspective view showing a main part of the second embodiment of the present invention, and FIG. 11 is a core of the second embodiment. FIG. 12 is a perspective view showing a part of a convex mold for molding the material, and a sectional view of a speaker unit using the speaker diaphragm of the present invention. 1... Sheet material, 2... Adhesive, 3, 3'...
Skin material, 4, 5, 9... Core material, 4a, 4b,
5b...Mountain part of core material, 5...Cell of core material, 5
b... Frame-shaped protrusion, 5c... Linear protrusion, 6...
...Concave part, 6a...Protrusion part, 7,10...Convex part, 7
a, 10a...Plug, 8...Plastic film, 11...Coupling cone, 12...Edge, 13...Diaphragm, 14...Frame, 15
...Damper, 16...Bobbin, 17...Voice coil, 18...Plate, 19...Magnet,
20...York.

Claims (1)

[Claims] 1. One surface has a large number of frame-shaped protrusions that are arranged continuously in the radial direction, and the other surface has linear protrusions that are arranged in the radial direction at the bottom of each of the frame-shaped protrusions. A speaker diaphragm comprising a core material made of plastic having a section, and skin materials disposed on both the front and back surfaces of the core material and bonded to the frame-shaped protrusion and the linear protrusion. 2. A core material having a large number of frame-shaped protrusions arranged continuously in the radial direction on one surface and a linear protrusion arranged in the radial direction at the bottom of each of the frame-shaped protrusions on the other surface. , a concave mold having protrusions having a shape corresponding to the frame-shaped protrusions described above, and a convex mold having plugs arranged at positions corresponding to the centers of the respective protrusions, are formed by molding a plastic film. A method for manufacturing a speaker diaphragm, characterized by bonding skin materials on the front and back sides.