JPS58182996A - Diaphragm for speaker - Google Patents

Abstract

PURPOSE:To obtain a diaphragm having high internal loss with light weight, by folding a rectangular plate in which different material of plates are laminated into zigzag, and expanding the plate so that one side is taken as an inner circumference and the other side is taken as an outer circumference, and bonding surface member on both sides of the frame member. CONSTITUTION:Plates 14 of different materials are laminated into a rectangular shape, the plate is folded into zigzag, and expanded into a ring shaped frame member 1 so that one side 14A is taken as the inner circumference and the other side 14B is taken as the outer circumference. The surface member 2 is bonded on both sides of the expanded member 1 to form a speaker diaphragm. The frame member 1 is formed with two layers such as paper, plastic sheet or metallic foil. Further, the frame member 1 is formed into a three-layered sandwich construction laminating metallic foil on both sides of the paper. The speaker diaphragm is made light in weight, allowing to attain high rigidity and high internal loss.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a 1F plate-shaped speaker diaphragm, and an object of the present invention is to provide a speaker diaphragm that is lightweight and has a rigidity of 11"6.

In general, most speaker diaphragms are made by paper-molding pulp, and the diaphragm has a cone shape.

As a result, the position of the sound source shifts between the center and the outer periphery of the cone, creating a phase difference, which causes the air within the cone to resonate, making it difficult to obtain even sound pressure frequency characteristics. On the other hand, a flat-plate speaker, in which the diaphragm is flat and the sound sources are aligned, is advantageous in flattening the frequency response without the front chamber effect seen in cone-type speakers. However, in the case of a flat plate diaphragm, when conventional paper is used, the rigidity against bending is low, and split vibration tends to occur from low frequencies, making it difficult to obtain flat frequency characteristics over a wide band. On the other hand, attempts have been made to use polymer foams such as expanded polystyrene as flat diaphragms, but these also have low rigidity and are not suitable as diaphragms. Therefore, a flat plate diaphragm with a sand inch structure that is lightweight and has high bending rigidity is considered. In recent years, planar diaphragms using a Nikum Sand Inochi structure have been adopted to achieve these goals. When using the so-called nodal drive method, in which the voice coil is bonded and driven at the nodal position at the wave number between the first resonances of the diaphragm, the first resonance is canceled out, and the C (high frequency limit frequency) can be significantly reduced. It is possible to obtain a wideband speaker. However, honey.

A diaphragm using a cam sandwich structure has a complicated structure and is therefore expensive. To solve this problem, we bent a rectangular plate into a zigzag shape, expanded it into an annular shape with the inner circumferential surface on the negative side and the outer circumferential surface on the other side, and glued both end surfaces. It has been considered to use a sandwich structure formed by bonding surface materials to both sides of an annular frame member as a diaphragm. In the sandwich structure, which is made by bending this rectangular plate in a zigzag pattern and bonding surface materials to both sides of the frame member, which is developed into an annular shape, the bending rigidity (XI) of the frame member as the core material is high. When assembling (1”f)
Desired from the standpoint of axiality. In addition, in order to improve the characteristics as a diaphragm, the specific elastic modulus CTL of the skeleton member as the core material must be adjusted.
It is desirable that Q') be high.

Conventionally, paper with a large EI has been used as the core material for the skeleton, but paper's EIe is small compared to aluminum, which is not desirable for the characteristics of the diaphragm, and it tends to deform due to humidity. was there.

The present invention solves these drawbacks of iM, and is made by bending a rectangular plate-like body, which is a stack of plate-like bodies made of different materials, into a zigzag shape, so that the -side surface is the inner circumferential surface.

Surface materials are bonded to both sides of a framework member that is expanded into an annular shape so that the other side becomes the outer periphery. According to this configuration, a material with a large EI and a material with a large Vl can be laminated as the frame member of one diaphragm, so the frame member as the core material of the diaphragm can be made most suitable. This increases the rigidity of the diaphragm, and f
h becomes high, and a broadband diaphragm can be obtained. Furthermore, since the bending rigidity of the frame member is improved, unnecessary vibrations are suppressed, a speaker with low distortion is obtained, and mechanical strength is also improved, increasing reliability during assembly.

Furthermore, by making the frame member a three-layer sandwich structure, it is possible to improve moisture resistance, which reduces deformation of the diaphragm and improves first-time reliability. It has the advantage of being able to

Hereinafter, the speaker diaphragm of the present invention will be explained with reference to drawings of embodiments.

FIG. 1 shows an embodiment of the present invention. In the figure, 1 is an annular skeleton member, and 2 is a surface material adhered to both sides of the annular skeleton member 1. As shown in FIG. The annular frame member 1 is made by bonding an aluminum foil 13 onto a craft paper 11 using an adhesive 12 as shown in FIG. It is bent in a zigzag shape and developed into an annular shape such that the inlet side of the side surface 14 is located on the inner peripheral surface and the other side surface 14B is located on the outer peripheral surface.

Specifically, the frame member 1 is made of 509 m thick kraft paper and dry laminated with 7 μm thick aluminum foil 11 via a urethane adhesive with an areal density of 7/1o/rn'.
A diaphragm having a thickness of 6 mm and a diameter of 190 mm was formed using rectangular plates laminated according to the formula.

The fh of the speaker using this diaphragm was 3.3 KHz, which was 0.2 KHz higher than the fh of the speaker using only kraft paper as a rectangular plate.

In addition, as shown in FIG. 4, the skeleton member 1 is formed by attaching a 7 μm thick aluminum foil 1 to both sides of a 3 μm thick kraft paper 11 with a urethane adhesive 12 having an areal density of 10 g/i.
A diaphragm similar to that described above was made by using rectangular plate-like bodies laminated by a dry lamination method. The fh of a speaker using this diaphragm is 3.6KHz, which is 0.0 compared to a speaker using only kraft paper as a rectangular plate.
．． There was an improvement of 5KHz.

Note that the aluminum foil 13 may be formed into a rectangular plate-like body by laminating the aluminum foil 13 on the paper 11 or a plastic sheet by vapor deposition, instead of using the dry lamination method.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway side view of the speaker diaphragm of the present invention;
Fig. 2 is a perspective view of the developed if1 of the frame member used in the same diaphragm, Fig. 3 is a cross-sectional view of a rectangular plate-like body consisting of two layers forming the same frame member, and Fig. 4 is a three-layer sand inch. FIG. 1... Skeleton member, 2... Surface material, 11.
...paper, 12...1 adhesive, 13...
...Aluminum foil. Name of agent: Patent attorney Uneo Nakao and 1 other person No. 1
Figure 2

Claims (3)

[Claims] (1) A rectangular plate made of stacked plates made of different materials is bent into a zigzag shape and developed into an annular shape with the inner surface on the negative side and the outer peripheral surface on the other side. A speaker diaphragm made by bonding surface materials to both sides of a frame member. (2) A diaphragm for a speaker according to claim 1, wherein a structure made of two layers of paper, plastic sheets, or metal foil is used as the frame member. (3) A diaphragm for a speaker according to claim 1, characterized in that a three-layer sandwich structure in which gold leaf is laminated on both sides of paper is used as the frame member.