JPS58114699A - Composite diaphragm - Google Patents

Abstract

PURPOSE:To obtain a composite diaphragm which is suited to a speaker, by using a core member in which the projected and depressed parts of trapezoidal and trigonal pyramid forms are regularly arranged in a prescribed relation with each other. CONSTITUTION:For a core member 11, a number of projected parts 12 formed into trapezoidal regular triangles with the same size are regularly arranged and in a prescribed formation. A surface member 14 is adhered to the upper surface side of an edge face part 12s of a regular triangle with use of an adhesive. At the same time, a surface member 15 is adhered to the lower surface side of an edge face part 13s of a regular triangle at each depressed part 13 with an adhesive. Therefore an equal adhered area is obtained between the members 14 and 15 to ensure a good balance of strength between both surface members. The member 11 as a whole has extremely large rigidity as the projected parts contiguous with each other are supported to each other. Furthermore its dyanamic characteristic becomes isotropic and the directivity of the bending strength is eliminated.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a composite diaphragm suitable for use as an acoustic diaphragm of a speaker, etc., and in particular, a core member to which a surface member is bonded is lightweight and has high rigidity. The present invention proposes an improved composite diaphragm having a structure that is extremely easy to manufacture.

Acoustic diaphragms used in speakers must be lightweight;
In particular, it is required to have high rigidity, to have isodirectional mechanical properties in a one-dimensional direction along the plate surface, and to be easy to manufacture. As a suitable diaphragm for JJR speakers, an IV combined diaphragm was proposed in the Cong. Yes, it is put into practical use.

Composite swing 1/υ plates using this honeycomb core material are usually
1 is a honeycomb core material, and skin materials 3 and 3 formed of aluminum foil or the like are adhered to the upper and lower surfaces of this honeycomb core material, respectively. As a whole, a flat diaphragm is constructed. The honeycomb core material/is usually bonded to the core material q as shown in Figure 2A! A large number of core materials 1 and 2 are provided, and the adhesive surfaces S and 2 of the core materials adjacent to each other are bonded to each other with an adhesive to form a large number of core materials. The water part of the honeycomb structure seen from the top, shown in thick lines, is the part where two core materials are bonded together with adhesive. In order to keep this in mind, a considerable amount of adhesive is consumed in manufacturing the honeycomb core material, and the weight of the completed honeycomb core material is the same as that of the consumed adhesive. In addition, the production of honeycomb core material is
This has the disadvantage that it cannot be said to be easy to manufacture because it requires many processes that require high precision, such as processing, adhering, and cutting the core material.

Furthermore, the structural unit of 1 honeycomb core material is a regular hexagonal prism, but it is not easy to form each hexagonal prism accurately and uniformly, and the cross section may be distorted or the axis may be tilted. As a result, the strength of the honeycomb core material/ is likely to change in such areas, and the rigidity of the completed honeycomb core material/ is greatly reduced in the direction along the bonding surfaces S and B. However, it also has the disadvantage that it is small in the direction perpendicular to the bonding surfaces S and B, and has anisotropic mechanical properties. Therefore, such honeycomb core material/
Composite diaphragms constructed using diaphragms are relatively heavy, tend to undergo local strength changes, exhibit anisotropic mechanical properties, and are difficult to manufacture. There are also disadvantages that make it undesirable as a speaker diaphragm.

Therefore, in place of the honeycomb core material, the present invention utilizes a new core member having a structure that does not have the disadvantages and drawbacks associated with the honeycomb core material, thereby creating a composite diaphragm suitable for the diaphragm of a speaker. This is what we provide. Embodiments of the present invention will be described below with reference to FIG. 3 and subsequent figures of the drawings.

FIG. 3 shows an example of a composite diaphragm according to the present invention, in which // is a core member, in which a large number of convex parts /2 formed in the shape of a truncated regular triangular pyramid have the same dimensions and a predetermined arrangement. Concave portions /3 formed in a regularly arranged manner and surrounded by a plurality of adjacent side wall portions of these convex portions /2;
are arranged in large numbers. This core member // has a convex portion /2
Since the concave portions and concave portions /3 are each shaped like a truncated triangular pyramid, the mold has a shape that corresponds to the arrangement of the convex portions /3 and concave portions /3, and can be used to mold lightweight plate materials such as seven sheets of paper or thin aluminum plates. It can be molded by punching. And the equilateral triangular end face portion of each convex portion 7.2 of the core member //
2. Adhesive is applied to the outer surface (upper surface) side (shaded part) of the surface member /1 to adhere it, and adhesive is applied to the outer surface (lower surface) side of the equilateral triangular end surface part /38 of each recess /3. Then, the surface member /S is bonded to form a composite diaphragm having a flat plate shape as a whole.

FIG. 9 is a plan view of the core member // described above.

As is clear from this figure, a plurality of truncated triangular pyramid-shaped convex portions/2
The directions of the corresponding inclined ridgelines are aligned and are regularly arranged at a certain interval, and each bottom apex is connected to the central part of the side wall bottom of the adjacent one. 2, where the equilateral triangle with vertices a, b and cf formed by the end face part /2s of the convex part /2 is A, B and Ct which should be formed by the base of the convex part /2. It is designed to be obtained at a height that is half the height of a triangular pyramid whose base is an equilateral triangle with an apex. -,
Therefore, the end face part /3 of the recess /3. The equilateral triangle formed by the vertices d, e, and fi is assumed to be an equilateral triangle a b c J: smaller. Also, the wells on each side of equilateral triangle ABC, SA AB
, BC and CA are t, and each side of the equilateral triangle A B C is set, which represents the amount of intrusion of the bottom 0'1 point of the convex part /2 into the center part of the side wall bottom of the adjacent one. ing.

By setting in this way, the area of the end face part /28 of the convex part /Ω and the area of the end face part /38 of the concave part /3 in the regular hexagon H represented by the dotted line are made equal. Ru. As is clear from the figure, the core member // is filled with a large number of regular hexagons H without gaps in plan view, and the regular hexagons H form unit sections. Therefore, with the above settings, in the entire core member //, the convex part /2
The sum of the areas of the end face portions /S and the sum of the areas of the end face portions /38 of the recesses /3 are made equal.

Here, the area of the end face part /2° of the convex part /2 and the area of the end face part ljm of the concave part /3 in the regular hexagon H are calculated.

The area of the end face part /28 of the convex part /2 in the regular hexagon H is the area of the regular triangle abc x 3, and the area of the end face part /28 of the convex part /2 in the regular hexagon H is the area of the regular triangle abc x 3. The area of part /3s is the area of the equilateral triangle def x B, which is the area of the end face part 72s of the convex part /2 in the square H and the end face part of the concave part /3 /38
It can be seen that the area of is equal to

Since the convex part /2 and the concave part /3 of the core member // are arranged and formed as described above, the outer surface side of the end face part /2s of the convex part /3 and the outer face side of the end face part /38 of the concave part /3. The adhesion areas for the surface members /G and /S to be adhered can be made equal, and as a result, after adhesion, the strength is balanced between the surface member llI side and the surface member 15 side. can do. In addition, since the bottom apex of each of the many truncated triangular pyramid-shaped convex portions is inserted into the central part of the side wall base of the adjacent one and combined and arranged, the core member// as a whole is The parts support each other ('・2), making it extremely rigid, and
The mechanical properties are isotropic and there is no directionality in bending strength.

As explained above, the plate-shaped core member of the present invention, unlike the honeycomb core material, can be manufactured extremely easily by molding seven eaves sill boards using the press V process. Since no adhesive is required, the weight of the finished product can be reduced, and the truncated triangular pyramid-shaped convex portions and concave portions are regularly arranged in a predetermined relationship.
It has extremely high rigidity and isotropic mechanical properties. Therefore, the composite diaphragm according to the present invention obtained by using such a plate-shaped core member and bonding surface members to both sides thereof is lightweight, has extremely high rigidity, and has a high rigidity in two-dimensional directions along the plate surface. It has isotropic mechanical properties and can be manufactured extremely easily. Furthermore, since the surface members on both sides are adhered to the respective end faces of the many truncated triangular pyramid-shaped protrusions and recesses of the core member, which are arranged so that the sum of the areas is equal, the adhesion is possible on both sides. The diaphragm has the advantage of being extremely strong and well-balanced, preventing peeling of the surface member from the core member and further increasing the strength of the entire diaphragm. Therefore, the composite diaphragm according to the present invention is superior to a composite diaphragm using a honeycomb core material in various aspects, and is suitable for an acoustic diaphragm used in a speaker.

[Brief explanation of the drawing]

Fig. 1 is a partially cutaway perspective view showing a composite diaphragm made entirely of conventional honeycomb core material, Fig. 2 is a diagram used to explain the honeycomb core material, and Fig. 3 is an example of the composite diaphragm according to the present invention. FIG. 9 is a plan view showing the core member in the example of FIG. 3. In the figure, // is the core member, /2 is the convex part, /3 is the concave part, /s and /33 are the end face parts, /q and /S are the surface Fig. 3■ +2 13 15

Claims (1)

[Claims] Each of them is formed in the shape of a truncated triangular pyramid, and the apex of each bottom enters the central part of the base of the side wall of the adjacent one, and has a large number of regularly arranged convex parts, each of which is one of the convex parts. A large number of recesses are formed surrounded by a plurality of adjacent side walls, such that the area of the end face of the convex part and the area of the end face of the recess within a unit section are approximately equal. A composite diaphragm comprising a surface member bonded to an outer surface of an end surface of the convex portion and an outer surface of an end surface of the recess of a formed plate-shaped core member.