JPH11289595A - Diaphragm for electroacoustic transducer and method of manufacturing the same - Google Patents

Abstract

(57) [Problem] To provide an electroacoustic transducer diaphragm having improved adhesive strength between a diaphragm main body and an edge, and a method of manufacturing the same. SOLUTION: The diaphragm main body 12 is provided so that an inner peripheral edge thereof is overlapped with an outer peripheral edge of the diaphragm main body 12, and is made of a material different from the material of the diaphragm main body. A diaphragm (diaphragm for electroacoustic transducer) 10 comprising an edge 14 of a mixed material, wherein the thickness of the outer peripheral edge of the diaphragm main body 12 is formed to be thinner than the thickness near the outer peripheral edge. The thickness of the inner peripheral edge is formed smaller than the thickness near the inner peripheral edge.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a diaphragm main body, which is provided so that an inner peripheral edge thereof is overlapped with an outer peripheral edge of the diaphragm main body. The present invention relates to a diaphragm for an electroacoustic transducer comprising an edge of a material obtained by mixing a foaming agent into a rubber component, and a method for producing the same.

[0002]

2. Description of the Related Art Conditions required for a diaphragm for an electroacoustic transducer (hereinafter referred to as a diaphragm in the present specification) are that the input signal has good linearity, that the reverse resonance phenomenon is unlikely to occur, and that sufficient reliability is obtained. It is easy to manufacture, inexpensive, and lightweight.

As the structure of the diaphragm, there has been proposed a fixed edge diaphragm in which the diaphragm main body and the edge are integrally formed, and a free edge diaphragm in which the diaphragm main body and the edge are separate members.

[0004] The manufacturing process of the fixed edge diaphragm is simplified because a step of bonding the diaphragm main body and the edge is unnecessary. However, since the material of the edge is a material having relatively high rigidity, which is the same as the material of the diaphragm main body, it is difficult to satisfy the conditions required for the above-described diaphragm.

On the other hand, since the free-edge diaphragm can be made of a different material from the diaphragm body and the edge, the above-mentioned conditions required for the diaphragm can be relatively easily achieved as compared with the fixed-edge diaphragm. In addition, a step of bonding the edge to the diaphragm main body is required, and there is a problem that the number of manufacturing steps increases.

In order to solve the problem of the free edge diaphragm, there has been proposed a method in which an edge is formed in a mold using an injection molding method, and at the same time, the diaphragm body and the edge are integrated.

However, the material of the edge manufactured by the conventional injection molding method is a solid structure.
(For example, various kinds of vulcanized rubbers, thermoplastic elastomers, etc.), there is a problem that the residual stress caused by shrinkage of the edge at the time of molding is not properly reduced, and the edge is largely deformed.

To solve this problem, a method as shown in FIG. 10 has been proposed. That is, first, as shown in FIG. (A), the preformed diaphragm main body 1 is set in one mold 2 of the mating mold, and then, as shown in FIG.
An edge base material 3 in which a foaming agent is mixed with rubber as a main component is set in one mold 2.

Then, as shown in FIG. 1C, when one mold 2 and the other mold 4 of the mating mold are heated, the edge base material 3 is melted and foamed, and the edge 5 is formed. Then, the diaphragm main body 1 and the edge 5 are integrated, and a diaphragm 6 having the edge 5 integrally formed on the outer peripheral edge of the diaphragm main body 1 is formed as shown in FIG.

[0010] By forming the edge 5 using this method, an excellent diaphragm having excellent acoustic characteristics and little deformation can be realized.

[0011]

However, the following problems also occur in the method of integrally forming the edge on the outer peripheral edge of the diaphragm body using rubber mixed with a foaming agent as the material of the edge. is there.

(1) Depending on the material of the diaphragm main body, the adhesive strength between the diaphragm main body and the edge decreases. (2) In a conventional free-edge diaphragm that uses an adhesive to bond the diaphragm body and the edge, an adhesive is interposed between the diaphragm body and the edge, and this adhesive provides some internal loss. As a result, the effect of preventing the reverse resonance phenomenon and dispersing the resonance due to the misalignment between the diaphragm main body and the edge can be obtained.

However, in the case of a diaphragm manufactured by a method in which a rubber mixed with a foaming agent is used as the material of the edge and the edge is integrally formed on the outer peripheral edge of the diaphragm main body, FIG.
As shown in (1), there is nothing interposed between the diaphragm main body 1 and the edge 5, and the diaphragm main body 1 and the edge 5 are in direct contact with each other and have excellent dimensional stability. A resonance phenomenon is likely to occur.

(3) Since the shape of the mold is complicated, the releasability between the edge and the mold is poor, and the maintenance of the mold is difficult.
Production efficiency decreases. For example, in FIG. 10 (d), the molten edge base material 3 contacts the surface 4 a of the other mold 4, but has an undercut surface, and when the other mold 4 is pulled out, the surface 4 a Surface 4a has poor releasability between the
The dirt easily accumulates on the surface.

Further, the dirt on the surface 4a is difficult to clean,
Maintenance is difficult. The present invention has been made in view of the above problems, and a first object of the present invention is to provide a diaphragm for an electroacoustic transducer in which the adhesive strength between the diaphragm main body and the edge is improved, and a method for manufacturing the diaphragm.

A second object of the present invention is to provide a diaphragm for an electroacoustic transducer in which a reverse resonance phenomenon is unlikely to occur, and a method for manufacturing the same. A third object is to provide an electroacoustic transducing diaphragm having good releasability between an edge and a mold, easy maintenance of the mold, and improved production efficiency, and a method of manufacturing the same.

[0017]

According to a first aspect of the present invention, there is provided a diaphragm main body, wherein the diaphragm main body is provided so that an inner peripheral edge thereof overlaps an outer peripheral edge of the diaphragm main body. And an edge made of a material obtained by mixing a foaming agent with rubber as a main component, and a thickness of an outer peripheral portion of the diaphragm main body. A diaphragm for an electro-acoustic transducer, wherein the diaphragm is formed to be thinner than the thickness near the portion, and the thickness of the inner peripheral edge of the edge is smaller than the thickness near the inner peripheral edge.

The thickness of the outer peripheral edge of the diaphragm main body is formed thinner than the thickness near the outer peripheral edge, and the thickness of the inner peripheral edge of the edge overlapping the outer peripheral portion of the diaphragm is thinner than the thickness near the inner peripheral edge. By forming, the area where the outer peripheral edge of the diaphragm main body and the inner peripheral edge of the edge are in contact increases, and the adhesive strength between the diaphragm main body and the edge increases.

The rigidity of the portion where the outer peripheral edge of the diaphragm main body overlaps the inner peripheral edge of the edge is intermediate between the rigidity near the outer peripheral edge of the diaphragm main body and the rigidity near the inner peripheral edge of the edge. Rigidity, and the reverse resonance phenomenon is unlikely to occur.

According to a second aspect of the present invention, the thickness of the portion where the outer peripheral edge of the diaphragm main body and the inner peripheral edge of the edge overlap with the thickness of the other portion of the edge according to the first aspect of the present invention. A diaphragm for an electroacoustic transducer characterized by being substantially the same.

By making the thickness of the portion where the outer peripheral edge of the diaphragm main body and the inner peripheral edge of the edge overlap with each other approximately the same as the thickness of the other portion of the edge, the surface on which the edge of the mold is formed can be formed. The undercut surface is eliminated, the releasability between the edge and the mold is good, the maintenance of the mold is easy, and the production efficiency is improved.

According to a third aspect of the present invention, the diaphragm main body is provided so that an inner peripheral edge thereof overlaps an outer peripheral edge of the diaphragm main body, and the diaphragm main body is made of a material different from the material of the diaphragm main body. A diaphragm for an electroacoustic transducer comprising an edge of a material obtained by mixing a foaming agent into a rubber component, and a first portion having a thickness substantially the same as a thickness near an outer peripheral portion on an outer peripheral portion of the diaphragm main body. A step is provided, and a second step engaging with the first step is provided at an inner peripheral edge of the edge with a thickness substantially equal to a thickness near the inner peripheral edge. It is a diaphragm for an acoustic transducer.

A first step portion having a thickness substantially the same as the thickness near the outer peripheral edge is provided on the outer peripheral edge of the diaphragm main body, and a thickness substantially the same as the thickness near the inner peripheral edge is provided on the inner peripheral edge of the edge. By providing the second step portion that engages with the first step portion, the area where the outer peripheral edge of the diaphragm main body contacts the inner peripheral edge of the edge increases, and the diaphragm main body and the edge And the adhesive strength increases.

Further, the first step of the diaphragm main body and the second step of the edge are engaged with each other, so that the surface forming the edge of the mold has no undercut surface, and the edge and the mold Good mold releasability, easy mold maintenance, and improved production efficiency.

According to a fourth aspect of the present invention, a diaphragm main body is provided so that an inner peripheral edge portion thereof overlaps an outer peripheral edge portion of the diaphragm main body, and is made of a material different from the material of the diaphragm main body. A method for manufacturing a diaphragm for an electroacoustic transducer comprising an edge of a material obtained by mixing a foaming agent into a rubber component, wherein a thickness of an outer peripheral portion is smaller than a thickness near an outer peripheral portion, and a diaphragm main body is formed. The diaphragm main body and a base material obtained by mixing a foaming agent with rubber as a main component are arranged in one mold of a mating mold, and the mold is clamped by using the other mold of the mating mold. And forming an edge with a thickness of the inner peripheral edge thinner than a thickness near the inner peripheral edge, and integrating the inner peripheral edge of the edge with the outer peripheral edge of the diaphragm. This is a method for manufacturing a diaphragm for a converter.

The thickness of the outer peripheral edge of the diaphragm main body is formed smaller than the thickness near the outer peripheral edge, and the thickness of the inner peripheral edge of the edge overlapping the outer peripheral portion of the diaphragm is smaller than the thickness near the inner peripheral edge. By forming, the area where the outer peripheral edge of the diaphragm main body and the inner peripheral edge of the edge are in contact increases, and the adhesive strength between the diaphragm main body and the edge increases.

The rigidity of the portion where the outer peripheral edge of the diaphragm main body and the inner peripheral edge of the edge overlap is intermediate between the rigidity near the outer peripheral edge of the diaphragm main body and the rigidity near the inner peripheral edge of the edge. Rigidity, and the reverse resonance phenomenon is unlikely to occur.

According to a fifth aspect of the present invention, the thickness of the portion where the outer peripheral edge of the diaphragm main body and the inner peripheral edge of the edge overlap with the thickness of the other portion of the edge according to the fourth aspect of the present invention. A method of manufacturing a diaphragm for an electroacoustic transducer, which is substantially the same.

The thickness of the portion where the outer peripheral edge of the diaphragm main body and the inner peripheral edge of the edge overlap with each other is made substantially the same as the thickness of the other portion of the edge, so that the surface on which the edge of the mold is formed can be formed. The undercut surface is eliminated, the releasability between the edge and the mold is good, the maintenance of the mold is easy, and the production efficiency is improved.

According to a sixth aspect of the present invention, the diaphragm main body is provided so that an inner peripheral edge thereof overlaps an outer peripheral edge of the diaphragm main body, and is made of a material different from a material of the diaphragm main body. A method of manufacturing a diaphragm for an electroacoustic transducer, comprising: an edge made of a material obtained by mixing a foaming agent into a rubber component; and forming a first step portion having a thickness substantially equal to a thickness near an outer peripheral edge portion on an outer peripheral edge portion. Forming a diaphragm main body having the diaphragm main body and a base material obtained by mixing a foaming agent with rubber as a main component are arranged in one mold of a mating mold, and using the other mold of the mating mold. After the mold is clamped, the mating die is heated to form an edge having a second step portion having a thickness substantially equal to that of the vicinity of the inner peripheral portion by engaging the first step portion with the inner peripheral portion. At the same time, the inner peripheral edge of the edge is integrated with the outer peripheral edge of the diaphragm for an electroacoustic transducer. It is a method of manufacturing a dynamic plate.

At the outer peripheral edge of the diaphragm main body, a first step having a thickness substantially equal to the thickness near the outer peripheral edge is provided, and at the inner peripheral edge of the edge, the thickness is substantially the same as the thickness near the inner peripheral edge. By providing the second step portion that engages with the first step portion, the area where the outer peripheral edge of the diaphragm main body contacts the inner peripheral edge of the edge increases, and the diaphragm main body and the edge And the adhesive strength increases.

Further, by engaging the first step portion of the diaphragm main body with the second step portion of the edge, the surface forming the edge of the mold has no undercut surface, and the edge and the mold Good mold releasability, easy mold maintenance, and improved production efficiency.

In the invention according to any one of claims 1 to 6, examples of the rubber which is a main component of the edge include:
There are vulcanized rubbers or thermoplastic elastomers. Here, as the vulcanized rubber, styrene-butadiene rubber, nitrile-
Some are selected from the group consisting of butadiene rubber, ethylene-propylene-terpolymer rubber, isoprene rubber, chloroprene rubber, isobutylene-isoprene rubber, ethylene-propylene rubber, and silicone rubber.

The thermoplastic elastomer is selected from the group consisting of polystyrene, polyolefin, polyurethane, polyester, polyamide, polybutadiene, ethylene-vinyl acetate, and polyvinyl chloride.

Further, as the foaming agent, there is a gas generating type by thermal decomposition, and the specific gravity of the foamed edge is 0.07 to
A range of 1.2 is preferred.

[0036]

Embodiments of the present invention will now be described with reference to the drawings. 1. First embodiment corresponding to the first, second, fourth and fifth aspects of the present invention FIG. 1 is a cross-sectional view of a diaphragm according to a first embodiment of the present invention, and FIG. Overall sectional view, (b)
The figure is an enlarged view of part A of FIG.

In FIG. 1A, the diaphragm 10 is provided so that the diaphragm main body 12 and the inner peripheral edge overlap the outer peripheral edge of the diaphragm main body 12 and are made of a material different from the material of the diaphragm main body 12. And an edge 14 made of a material obtained by mixing a foaming agent into rubber as a main component.

Then, as shown in FIG. 2B, a first step 16 is provided on the back side of the outer peripheral edge of the diaphragm main body 12, and a diaphragm main body is provided on the front side of the inner peripheral edge of the edge 14. A second step 18 is formed which engages the first step 16 of the twelve.

The thickness T 'of the first step 16 formed on the outer peripheral edge of the diaphragm main body 12 is formed to be smaller than the thickness T near the outer peripheral edge. The thickness t 'of the second step 18 formed on the inner peripheral edge of the edge 14 is formed to be smaller than the thickness t near the inner peripheral edge.

Further, the outer peripheral edge of the diaphragm 12 and the edge 14
The thickness (T '+ t') of the portion overlapping the inner peripheral edge of the edge 14 is set to be substantially the same as the thickness (t) of the other portion of the edge 14.

Next, a method of manufacturing the diaphragm 10 having the above-described structure will be described with reference to FIGS. Manufacture of diaphragm main body (see FIG. 2) (1) Pulp made of 100% wood fiber is formed into a predetermined shape to obtain diaphragm main body material 12 '(see FIG. 2 (a)).

(2) The diaphragm main body material 12 ′ is
2 and heat (200 ° C) for about 100 seconds, compress and dry (Fig.
(See (b)) and (c) as shown in the figure, a diaphragm main body material 12 ″ on which the first step 16 is formed is obtained.

(3) Central part 12 of diaphragm main body material 12 ″
a "and the outer peripheral portion 12b" are removed, and the first peripheral portion is removed.
The diaphragm main body 12 is formed with the step 16 (see FIG. (D)).

Incidentally, between (2) and (3), the molds 21 and 22 may be used to reheat (200 ° C.) and recompress for about 5 seconds. Integral molding of diaphragm main body and edge (see FIG. 3) (1) Set first diaphragm main body 12 having first step 16 formed on the outer peripheral edge in one mold 31 of the mating die. Do
(See (a) figure).

(2) An edge substrate 33 made of a material obtained by mixing a foaming agent with rubber as a main component is set in one mold 31 of the mating mold (see FIG. 2B). Examples of the rubber that is the main component of the edge base material 33 include vulcanized rubber or thermoplastic elastomer.

Here, the vulcanized rubber includes styrene-butadiene rubber, nitrile-butadiene rubber, ethylene-propylene-terpolymer rubber, isoprene rubber, chloroprene rubber, isobutylene-isoprene rubber, ethylene-propylene rubber, and silicone rubber. Some are selected from a group.

The thermoplastic elastomer may be selected from the group consisting of polystyrene, polyolefin, polyurethane, polyester, polyamide, polybutadiene, ethylene-vinyl acetate, and polyvinyl chloride.

Further, as the foaming agent, there is a gas generating type by thermal decomposition, and the specific gravity of the foamed edge is 0.07 to
A range of 1.2 is preferred. (3) The other mold 35 of the mating mold
After the mold is clamped by using, the mating mold 37 is heated. Then, while the viscosity of the edge base material 33 decreases, it foams,
The edge 14 having the second step 18 formed on the inner peripheral edge thereof in the space formed between one mold 31 and the other mold 35.
Is formed. At this time, the inner peripheral edge of the edge 14 and the outer peripheral edge of the diaphragm main body 12 are adhered and integrated by the self-adhesive force of the edge base material 33 (see FIG. 3C).

In this embodiment, one of the molds 31 is used.
The diaphragm main body 12 and the edge 14 integrally formed by using the mating die 37 including the other mold 35 overlap the outer peripheral edge of the diaphragm main body 12 and the inner peripheral edge of the edge 14. The thickness (T '+ t') of the portion is formed so as to be substantially the same as the thickness (t) of the other portion of the edge 14.

The diaphragm 10 and the diaphragm 1 having the above configuration
According to the manufacturing method No. 0, the following effects can be obtained. (1) As shown in FIG. 4 (b), in the conventional diaphragm, the back surface of the outer peripheral edge of the diaphragm main body 1 and the surface of the inner peripheral edge of the edge 5 abut and are bonded.

On the other hand, in the present embodiment, as shown in FIG. 4A, a first step 16 is provided on the back side of the outer peripheral edge of the diaphragm main body 12 so that the outer side of the diaphragm main body 12 is provided. The thickness of the peripheral portion is made thinner than the thickness in the vicinity of the outer peripheral portion, and a second side is provided on the surface side of the inner peripheral portion of the edge 14 overlapping the outer peripheral portion of the diaphragm main body 12.
And the thickness of the inner peripheral edge of the edge 14 is made thinner than the thickness near the inner peripheral edge, so that not only the rear surface of the outer peripheral edge of the diaphragm main body 12 and the outer peripheral surface of the edge 14 but also The end surface of the diaphragm main body 12 contacts the edge 14, and the end surface of the edge 14 contacts the diaphragm main body 12.

Therefore, as compared with the conventional diaphragm, the area where the outer peripheral edge of the diaphragm main body 12 and the inner peripheral edge of the edge 14 are in contact increases, and the adhesive strength between the diaphragm main body 12 and the edge 14 increases. .

(2) As shown in FIG. 4 (b), in the conventional diaphragm, the rigidity rapidly changes at a portion where the inner peripheral edge of the diaphragm main body 1 and the outer peripheral edge of the edge 5 overlap. On the other hand, FIG.
As shown in FIG. 5, in the present embodiment, the rigidity of the portion where the outer peripheral edge of the diaphragm main body 12 and the inner peripheral edge of the edge 14 overlap with each other is:
The rigidity in the vicinity of the outer peripheral edge of the diaphragm main body 12 and the rigidity in the vicinity of the inner peripheral edge of the edge 14 are intermediate rigidities, and the reverse resonance phenomenon is unlikely to occur.

(3) Outer peripheral edge and edge 1 of diaphragm main body 12
By making the thickness of the portion where the inner peripheral edge portion of the mold 4 overlaps with the thickness of the other portion of the edge 14 substantially the same, the undercut surface is formed on the surface forming the edge 14 of the molds 31 and 35 of the mating die 37. The edge 14 and the molds 31 and 35 have good releasability, and the maintenance of the molds 31 and 35 is easy.
The present invention is not limited to the above-described embodiment.

For example, as shown in FIG. 5A, the outer peripheral edge of the diaphragm main body 12 has a surface opposite to that of the embodiment, that is,
The first step portion 41 is provided on the front surface side, and the thickness of the outer peripheral edge portion of the diaphragm main body 12 is formed thinner than the thickness near the outer peripheral edge portion,
Also, the inner peripheral edge of the edge 14 has a surface side opposite to that of the embodiment,
That is, the second step portion 43 is provided on the back surface side, and the thickness of the inner peripheral edge portion of the edge 14 is formed thinner than the thickness near the inner peripheral edge portion,
The outer peripheral edge of the diaphragm main body 12 and the inner peripheral edge of the edge 14 may be overlapped.

As shown in FIG. 5 (b), the thickness of the outer peripheral edge of the diaphragm main body 12 is reduced stepwise, and the thickness of the inner peripheral edge of the edge 14 is reduced stepwise. The outer peripheral edge portion 12 and the inner peripheral edge portion of the edge 14 may be overlapped.

As shown in FIG. 5 (c), the thickness of the outer peripheral edge of the diaphragm main body 12 is reduced in a wavy line, and the thickness of the inner peripheral edge of the edge 14 is reduced in a wavy line. The outer peripheral edge of the main body 12 and the inner peripheral edge of the edge 14 may be overlapped.

As shown in FIG. 5D, the thickness of the outer peripheral edge of the diaphragm main body 12 is gradually reduced, and the thickness of the inner peripheral edge of the edge 14 is gradually reduced. The outer peripheral edge portion 12 and the inner peripheral edge portion of the edge 14 may be overlapped.

As shown in FIG. 5E, a first step 45 is formed on the front side of the outer peripheral edge of the diaphragm main body 12, and a second step 47 is formed on the back side thereof. The convex portion 49 may be provided on the outer peripheral end surface of the diaphragm 14, and the concave portion 51 with which the convex portion 49 of the diaphragm main body 12 engages may be formed on the inner peripheral end surface of the edge 14.

2. The second invention corresponding to the third and sixth aspects of the invention.
Next, a second embodiment will be described with reference to FIG.

In FIG. 6A, a first step portion 61 having a thickness substantially the same as the thickness near the outer peripheral edge is formed on the outer peripheral edge of the diaphragm main body 12 so as to protrude to the rear surface side. In the part, it protrudes to the surface side and is almost the same as the thickness near the inner peripheral edge,
A second step 63 that engages with the first step 61 of the diaphragm main body 12 is formed.

The diaphragm having such a shape is manufactured by using one mold 65 and the other mold 67 of the mating mold.
Since the manufacturing method is the same as that of the first embodiment, the description is omitted.

According to the diaphragm and the method of manufacturing the diaphragm having the above-described configuration, the following effects can be obtained. (1) As in the first embodiment, the contact area between the diaphragm main body 12 and the edge 14 increases the adhesive strength between the diaphragm main body 12 and the edge 14.

(2) First step 61 of diaphragm main body 12
The engagement of the second step 63 of the edge 14 with the second step 63 eliminates the undercut surface on the surface forming the edge 14 of the molds 65 and 67, and improves the releasability between the edge 14 and the molds 65 and 67. Good maintenance of the molds 65 and 67 is easy, and production efficiency is improved.

The present invention is not limited to the above embodiment. For example, as shown in FIG. 6 (b), a first step portion 71 which protrudes toward the front surface side and is substantially the same in thickness in the vicinity of the outer peripheral edge is formed on the outer peripheral edge of the diaphragm main body 12, and
Even if a second step 73 is formed on the inner peripheral portion of the diaphragm 4 to project to the rear surface side and has substantially the same thickness as the vicinity of the inner peripheral edge, and engages with the first step 71 of the diaphragm main body 12. The same effects as those of the diaphragm having the above-described configuration and the method of manufacturing the diaphragm can be obtained.

[0066]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present inventors conducted the following experiments to confirm the effects of the present invention. Experiment 1. Adhesive strength between diaphragm and edge According to the conventional manufacturing method and the manufacturing method of the first embodiment, five diaphragms each having a diameter of 160 mm were manufactured, as shown in FIG. A 15 mm wide sample was cut out at 90 ° division.

Accordingly, the number of samples of the conventional diaphragm is 20, and the number of samples of the diaphragm of the present invention is 20. The tensile strength of all these samples was investigated. The tensile tester used was
STOROGRAPH R (Toyo Seiki), with a pulling speed of 50mm
/ min.

As can be seen from FIG. 8 showing the result, it was confirmed that the adhesive strength between the diaphragm and the edge was improved. Experiment 2 Frequency sound pressure characteristics The frequency sound pressure characteristics of the conventional diaphragm manufactured in Experiment 1 and the diaphragm of the present invention were examined. It has been confirmed that the diaphragm of the present invention has a smoother characteristic than the conventional diaphragm, and no reverse resonance phenomenon occurs.

[0069]

As described above, according to the diaphragm for an electroacoustic transducer according to the first aspect and the method for manufacturing the diaphragm for an electroacoustic transducer according to the fourth aspect, the outer peripheral edge of the diaphragm main body is provided. The thickness of the part is formed thinner than the thickness near the outer peripheral edge,
By forming the thickness of the inner peripheral edge of the edge overlapping the outer peripheral portion of the diaphragm thinner than the thickness near the inner peripheral edge, the area where the outer peripheral edge of the diaphragm main body and the inner peripheral edge of the edge come into contact increases. As a result, the adhesive strength between the diaphragm body and the edge increases.

The rigidity of the portion where the outer peripheral edge of the diaphragm main body and the inner peripheral edge of the edge overlap is intermediate between the rigidity near the outer peripheral edge of the diaphragm main body and the rigidity near the inner peripheral edge of the edge. Rigidity, and the reverse resonance phenomenon is unlikely to occur.

According to the electroacoustic transducer diaphragm of the second aspect and the method of manufacturing the electroacoustic transducer diaphragm of the fifth aspect, the outer peripheral edge of the diaphragm main body and the inner peripheral edge of the edge are provided. By making the thickness of the portion where the portion overlaps approximately the same as the thickness of the other portion of the edge, there is no undercut surface on the surface forming the edge of the mold, and the releasability between the edge and the mold is reduced. Good mold maintenance is easy and production efficiency is improved.

According to the third aspect of the invention, there is provided a diaphragm for an electro-acoustic transducer, and a method of manufacturing a diaphragm for an electro-acoustic transducer according to the sixth aspect. A first step having a thickness substantially equal to the thickness of the first step, and a second step engaging with the first step at an inner peripheral edge of the edge having a thickness substantially equal to a thickness near the inner peripheral edge. Providing the step increases the area where the outer peripheral edge of the diaphragm main body and the inner peripheral edge of the edge come into contact, and increases the adhesive strength between the diaphragm main body and the edge.

The first step of the diaphragm main body and the second step of the edge are engaged with each other, so that the surface forming the edge of the mold has no undercut surface. Good mold releasability, easy mold maintenance, and improved production efficiency.

[Brief description of the drawings]

FIG. 1 is a sectional view of a diaphragm according to an embodiment of the present invention;
(a) is an overall sectional view, and (b) is an enlarged view of a portion A in (a).

FIG. 2 is a diagram illustrating a method of manufacturing the diaphragm main body shown in FIG.

FIG. 3 is a view for explaining a method of integrally forming the diaphragm main body and the edge shown in FIG. 1;

FIG. 4 is a diagram illustrating the effect of the first embodiment.

FIG. 5 is a diagram illustrating another example of the first embodiment.

FIG. 6 is a diagram illustrating a second embodiment.

FIG. 7 is an explanatory diagram of a sample used in Experiment 1 of Example.

FIG. 8 is a diagram showing the results of Experiment 1 of the example.

FIG. 9 is a diagram showing the results of Experiment 2 of the example.

FIG. 10 is a diagram illustrating a conventional example.

[Explanation of symbols]

 10 diaphragm (diaphragm for electroacoustic transducer) 12 diaphragm main body 14 edge

Claims (6)

[Claims] 1. A diaphragm main body, and an inner peripheral edge portion is provided so as to overlap an outer peripheral edge portion of the diaphragm main body. The diaphragm main body is made of a material different from the material of the diaphragm main body, and a foaming agent is added to rubber as a main component. Wherein the thickness of the outer peripheral edge of the diaphragm main body is formed to be thinner than the thickness near the outer peripheral edge, and the thickness of the inner peripheral edge of the edge. A diaphragm for an electroacoustic transducer, wherein the diaphragm is formed to be thinner than the thickness near the inner peripheral edge. 2. The thickness of a portion where an outer peripheral edge of the diaphragm main body and an inner peripheral edge of the edge overlap with each other is substantially the same as the thickness of another portion of the edge. Diaphragm for electro-acoustic transducer. 3. A diaphragm main body, and an inner peripheral edge portion is provided so as to overlap an outer peripheral edge portion of the diaphragm main body. The diaphragm main body is made of a material different from the material of the diaphragm main body, and a foaming agent is added to a rubber as a main component. A diaphragm of an electroacoustic transducer comprising an edge made of a material mixed with: a first step portion having a thickness substantially the same as a thickness near an outer peripheral portion is provided on an outer peripheral edge of the diaphragm main body; A diaphragm for an electroacoustic transducer, characterized in that a second step engaging with the first step is provided at an inner peripheral edge of the edge with a thickness substantially equal to a thickness near the inner peripheral edge. 4. A diaphragm main body and an inner peripheral edge portion are provided so as to overlap an outer peripheral edge portion of the diaphragm main body. The diaphragm main body is made of a material different from the material of the diaphragm main body, and a foaming agent is added to rubber as a main component. A method of manufacturing a diaphragm for an electroacoustic transducer, comprising: a diaphragm body having an outer peripheral edge portion having a thickness smaller than a thickness near an outer peripheral edge portion; A base material in which a foaming agent is mixed with rubber as a main component is arranged in one mold of a mating mold, and the mold is clamped using the other mold of the mating mold. Manufacturing an edge having a thickness smaller than a thickness near an inner peripheral edge portion and simultaneously integrating an inner peripheral edge portion of the edge with an outer peripheral edge portion of the diaphragm. Method. 5. The thickness of a portion where an outer peripheral edge of the diaphragm main body and an inner peripheral edge of the edge overlap with each other is substantially the same as the thickness of another portion of the edge. A method for manufacturing a diaphragm for an electroacoustic transducer according to the above. 6. A diaphragm main body, and an inner peripheral edge portion is provided so as to overlap an outer peripheral edge portion of the diaphragm main body. The diaphragm main body is made of a material different from the material of the diaphragm main body, and a foaming agent is added to rubber as a main component. A method for manufacturing a diaphragm for an electro-acoustic transducer, comprising: a diaphragm main body having a first step portion having a thickness substantially equal to a thickness near an outer peripheral edge portion on an outer peripheral edge portion. Then, the diaphragm main body and a base material obtained by mixing a foaming agent with rubber as a main component are arranged in one mold of a mating mold, and after clamping with the other mold of the mating mold, Heating the mating die to engage the first step on the inner periphery to form an edge having a second step having a thickness substantially equal to the thickness near the inner periphery; A method for manufacturing a diaphragm for an electroacoustic transducer, wherein an inner peripheral edge of the edge is integrated with an outer peripheral edge of the diaphragm.