JPS60219897A - Manufacture of ring-shaped flat diaphragm - Google Patents

Abstract

PURPOSE:To obtain a ring-shaped flat diaphragm having a stable strength in the circumferential direction by mounting a circular flat diaphragm produced by rotational spinning on a jig which insures easy positioning and will not deform the diaphragm and removing its center part. CONSTITUTION:A jig 7 consists of an upper part 7a and a lower part 7b and includes a space 8 which is slightly larger in outer diameter and smaller in thickness than a diaphragm in its inside. A hole 9 having a slightly larger inner diameter than that of a ring-shaped flat diaphragm is provided on the upper part 7a of the jig 7. A groove 11 for causing the tip of a blade to escape is provided on the lower part 7b in the vicinity of the inner diameter of the ring-shaped flat diaphragm. The diaphragm is placed on the jig 7 constituted in such a way and fixed by jig fitting parts 13. While a projection 10 is fited on a lathe, etc., and rotated, it is machined in its inner diameter in the direction of an arrow D. At the time of this machining the diaphragm will not move in the jig 7, and the drilling can be performed properly.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates primarily to a method for manufacturing ring-shaped flat diaphragms in a simple manner and in large quantities with excellent quality.

Structures of conventional examples and their problems In recent years, flat plate diaphragms made of a core material made of foam or foamed plastic and surface materials adhered to both sides have been widely used as diaphragms for speakers. These flat diaphragms use a driving method commonly called nodal driving, in which a node in a resonant mode in which one concentric node is generated is driven to eliminate the resonance and expand the reproduction band. On the other hand, in a circular flat plate diaphragm that uses a honeycomb core stretched in one direction as the core material, these nodes are not circular, so a rotationally stretched core is used in which the core material is rotated and stretched in the radial direction to make the rigidity uniform in the circumferential direction. A circular flat plate diaphragm is used. In addition, there is a coaxial speaker that uses a ring-shaped flat plate diaphragm and places a high-pitched speaker in the center.
It has been put into practical use due to its excellent localization of reproduced sound.

A conventional method for manufacturing a ring-shaped flat diaphragm will be described below. Regarding the manufacturing method of flat plate diaphragms by rotational expansion, Patent Registration No. 1104248 and Patent Registration No. 1128557
Rights have been established in this issue.

These are the manufacturing methods for ordinary flat plate diaphragms without holes in the center (.), but ring-shaped flat plate diaphragms are also manufactured by this method. The difference is that when the core 1 is spread out into a circular plate shape, a spacer 2 for forming a central hole is placed in the center part 1a, and the core 1 is arrowed around the spacer 2, b'
The ring-shaped flat plate diaphragm 4 is formed by stretching the ring-shaped surface materials 3a and 3b in the direction of .

When manufacturing the ring-shaped flat plate diaphragm 4 using the method described above, the core 1 is opened more widely toward the outer periphery, so that the reaction force becomes stronger toward the outer periphery of the core. For this reason, a force is constantly acting on each cell that makes up the core to shrink toward the inner periphery. The force acting on the innermost cell is extremely large. The cell must support this reaction force, but in the case of a normal circular flat diaphragm cell using the core 5 shown in Figure 2, the cell is not deformed because the density in the center is high and they reinforce each other. In the case of ring-shaped cells, the cell density is low, so each cell must independently support the force acting toward the inner periphery. 20μm
It is easily deformed because only a small amount is used. For this reason, when a ring-shaped rotationally expandable core is produced, the cells are not regularly arranged concentrically as shown in FIG. 3, but are deformed as shown in FIG. 4.

This deformation of the cell causes variations in strength, the nodes do not become circular, the sound pressure frequency characteristics are not flat, and distortion increases.

OBJECTS OF THE INVENTION The present invention solves the above-mentioned conventional drawbacks, and aims to provide a simple method for manufacturing ring-shaped flat plate diaphragms with excellent characteristics in large quantities.

Structure of the Invention The present invention has a circular flat plate diaphragm made by rotary expansion vibration, which is inserted into a jig that is easy to position and does not deform the diaphragm, and by removing the center part, the strength is constant in the direction of the circle bJ. A ring-shaped flat plate diaphragm can be easily produced.

DESCRIPTION OF EMBODIMENTS A method of manufacturing a ring-shaped flat diaphragm according to an embodiment of the present invention will be described below with reference to the drawings. First of all, the fifth
A circular flat plate diaphragm (hereinafter simply referred to as a diaphragm) is created by the usual rotary expansion 'jJv: method shown in the figure. Furthermore, 3a,
3b is a surface material, and 5 is a core. Next, this diaphragm 6 is inserted into a jig 7 shown in FIG. 6, and the diaphragm 6 is fixed. The jig will be explained in detail below. The jig 7 is divided into two parts, an upper part 7a and a lower part 7b, and has a space 8 on the inside that is equal to or slightly larger than the outer diameter of the diaphragm and whose depth is equal to or slightly shallower than the diaphragm thickness. It consists of

The upper portion 7a of the jig 7 is provided with a hole 9 that is slightly larger than the inner diameter of a ring-shaped flat diaphragm (not shown). The other lower part 7b has a protrusion 10 on its outer surface for attachment to a lathe tongue, and a groove 11 for letting the cutting edge escape on its inner surface is provided close to the inner diameter of the ring-shaped flat diaphragm. A diaphragm 6 is placed below this jig 7.
After placing the jig 7 on the upper portion 7a, insert the jig fixing part 13 in the direction of arrow A and fix the jig 7 at several places. Note that a screw-in type, a buckle type, etc. may be used to fix the jig divided into upper and lower parts. Now, the misalignment in inserting the diaphragm 6 into this jig 7 is because the inner diameter of the space 8 is equal to or slightly larger than the outer diameter of the diaphragm 6, so the processing center can be determined easily. Since it is equal to the height or only slightly lower, the diaphragm will be weakly crimped. Since the core 5 itself has spring properties, the shape of the diaphragm will not be deformed if it is removed from the jig 7 after processing. If the diaphragm 6 is weakly crimped to the jig 7 and inserted into the jig 7 in this way, the contact area between the jig and the diaphragm 6 is large, so the diaphragm 6 is strongly pressed against the jig 7 by friction. It is fixed and does not move inside the jig 7 during processing. Therefore, deformation does not occur in the vicinity of the pawl, unlike when it is fixed to a lathe or the like with a pawl or the like. In addition, the diaphragm 6 to be cut is held by the jig 7 near the cutting part, and the other side is held entirely except for the groove 11 for letting the cutting edge escape, so that the core 5 and the surface by crimping the cutting edge, Deformation of 14'3a, 3b can be reduced. This jig 1 may be provided with a stomach-retaining layer 12 on the inner wall surface of the internal space 8 to protect the diaphragm surface, as shown in FIG. 6(b). For this protective layer 12, materials such as cloth, felt, leather, rubber, plastic, etc., which have a large loss and a large coefficient of surface friction, are suitable. If this jig is rotated as shown by arrows B and C and the central portion is removed at the portions indicated by arrows B and E, the ring-shaped flat plate diaphragm 14 shown in FIG. 7 is obtained. Since the core at the inner diameter portion has already been covered with the surface materials 3a and ab, its position is stable and there is very little deformation even when cutting force is applied. Therefore, the shape of the core when first rotated and expanded can be maintained. Figure 8 is a schematic cross-sectional view of a ring-shaped V-plate diaphragm in another embodiment, which was cut so that the inner diameter cross section was inclined. It is something.

As described above, according to this embodiment, when the core 5 is rotated and expanded, it is made into a disk shape, so that deformation of the core due to force directed toward the center is prevented, and even when the center is removed, the core is not deformed. The core shape is uniform in the circumferential direction and the rigidity is uniform. The ring-shaped flat plate diaphragm 14 according to the present invention has circular nodes, and if these nodes are driven by a circular voice coil, the nodes can be driven completely.

Effects of the Invention In the present invention, since a circular flat diaphragm is cut into a ring shape, non-uniformity in rigidity does not occur. Because of trench cutting, circles with any inner diameter can be easily made with high precision, and the cross-sectional shape of the inner diameter can also be easily made. The jig holds the diaphragm with just contact, and since most of the diaphragm is protected by the jig, deformation of the diaphragm during cutting can be prevented, and the center of machining is based on the outside diameter of the diaphragm. can be easily determined, and its effects are significant.

[Brief explanation of the drawing]

Figures 1 (a) to (e) are process diagrams showing the conventional manufacturing method of a ring-shaped flat plate diaphragm, Figure 2 is a configuration diagram of the core of the same circular flat plate diaphragm, and Figure 3 is a diagram showing the structure of the core of the circular flat plate diaphragm. Fig. 4 is a partially cutaway top view of the ring-shaped flat diaphragm showing the state of deformation of the core by the conventional manufacturing method, and Fig. 6(a)->(→ 6(-) and (b) are diagrams showing the configuration of the same jig, and FIG. 8 is a partially cutaway top view of the ring-shaped flat plate diaphragm, and FIG. 8 is a sectional view of the ring-shaped flat plate diaphragm in another embodiment. 3a, 3b...Surface material, 6... ...core, 6
... circular flat plate diaphragm, 7 ... jig, 8 ... space, 9 ... hole, 11 ... groove. Name of agent: Patent attorney Toshio Nakao and 1 other person 2nd
Figure 3 Figure 4 Figure 5 Figure 6 (¥1

Claims (2)

[Claims] (1)°The core material is a lightweight, highly rigid thin foil made of metal, plastic, paper, etc., and is formed by rotating and expanding the hexagonal cells so that they are aligned in the radial direction. , a circular flat diaphragm formed by bonding a surface material such as paper, and a division that forms a space that is equal to or slightly larger than the outer diameter of the circular flat diaphragm and whose height is equal to or slightly lower than the height of the diaphragm. One side of the jig has a hole larger than the inner diameter of the ring-shaped flat plate diaphragm, and the other side has a groove for holding a cutting tool such as a cutting tool. A method for manufacturing a ring-shaped flat plate diaphragm, which comprises inserting a diaphragm and removing the central part of the circular diaphragm by cutting. (2) Claim 1 in which a protective layer is provided on the inner wall of the jig
Method for manufacturing glue/glue-shaped flat plate diaphragms described in Section 1.