JPS61196699A - Flat diaphragm - Google Patents

Abstract

PURPOSE:To generate the characteristic frequency in the small conic body that each small conic body itself plays the role of each trumpet, by composing of the integration of many small hollow conic bodies for flat diaphragm, and arranging the peripheral walls of each small conic bodies in a symplectic way against the board face direction of the diaphragm. CONSTITUTION:A flat diaphragm is constituted by a plate form substrate A by the coupling of many hollow square conic bodies 1, 1, 1 ... Then, these hollow square conic bodies have a shape cutting each bottom 2, 2, 2 ..., put in order placing each top 3, 3, 3 ... on the same plane, has a shape to joint each 4 sides constituting the bottom to each sides of the adjacent hollow square conic bodies, and these are molded by the sheet materials. Then, these hollow conical material have a shape cutting each bottom 5, 5, 5 ... similarly, each top 6, 6, 6 ... is put in order by locating on the same plane, and, are of shape mutually jointed with each peripheral edge of the hollow conical materials adjacent to each peripheral edge constituting the bottom, and these are also molded from 1 sheet-shaped material.

Description

[Detailed Description of the Invention] [Field of Industrial Application] This invention relates to a flat diaphragm that can be suitably used in acoustic transducers such as speakers and microphones, and uses a core material with a unique configuration. By doing so, it is intended to improve the speaker characteristics, etc.

[Conventional technology]

For example, conventional diaphragms for speakers are broadly divided into cone-shaped diaphragms made of paper into a cone shape, and planar diaphragms made of hollow thick plates with a honeycomb core sandwiched between two skins. can do.

Among the conventional diaphragms mentioned above, honeycomb core type planar diaphragms have become increasingly popular in recent years due to their relatively good acoustic properties and ease of manufacture compared to cone-shaped diaphragms. It's increasing.

[Problem that the invention seeks to solve]

Due to its structure, the honeycomb core type planar diaphragm has poor rigidity in the lateral direction, so the front and back sides of the core are sandwiched between surface plates to maintain the rigidity in the lateral direction.

However, the hollow portion of the honeycomb core having such a conventional structure inevitably has a structure that is isolated from the outside.

In such a structure, when an audio current is applied to the voice coil attached to the back side of the honeycomb core type flat diaphragm, the heat generated by the voice coil is transmitted to the front plate, causing the air in the closed hollows of each core to expand. This has the disadvantage of causing destruction or deformation of the surface plate.

In addition, the mechanism of acoustic generation in the honeycomb core type planar diaphragm is that the air mass in the hollow part composed of the honeycomb core is added to the vibrating mass, so the driving force applied to the diaphragm, i.e. , the vibration power must be large.

[Means for solving problems]

The inventors of this invention have eliminated as much as possible the isolation of the core hollow part of the honeycomb core type planar diaphragm from the outside,
We conducted intensive research to create a planar diaphragm with lower vibration power and superior vibration frequency characteristics, especially in the high frequency range, which is different from conventional planar diaphragms, and this invention was completed. The device is characterized in that it consists of a plate-shaped base having a plurality of hollow cones with their bottoms cut out, the tops of which are positioned on the same plane and connected adjacently to each other.

As described above, this invention comprises a plate-shaped base constituted by a collection of a large number of hollow cones with the bottom surfaces cut out, and the plate-shaped base corresponds to the core of the above-mentioned honeycomb core type planar diaphragm. As the hollow pyramid, various types of pyramids such as triangular pyramids, square pyramids, pentagonal pyramids, etc. can be used, and cones can also be used. can.

In the case of a cone, the centers of the circles on the bottom surface may be arranged on the same line, or may be arranged in a so-called staggered arrangement, in which the centers are arranged on different lines alternately.

[For production]

The planar diaphragm of the present invention is composed of a large number of small hollow cones, and the peripheral wall of each small cone is arranged obliquely with respect to the plate surface direction of the diaphragm. Each cone itself acts as a trumpet, generating a high natural frequency on the surface of the small cone, and also functions as a high-frequency vibrator, producing acoustic effects with characteristics different from those of conventional flat diaphragms. It is something that can be done.

There are various ways in which the flat diaphragm is used in this invention, as will be clear from the examples below, but in all of them, it is formed in the hollow part of a hollow cone or on the outer periphery of a hollow cone when vibration is generated in practical use. This creates a different effect from that of a conventional honeycomb core type flat diaphragm, and this reduces the heat generation of the voice coil, which occurs in the surface plate (sheet material), as seen in honeycomb core type flat diaphragms. Obstacles such as deformation and damage are completely eliminated, and the air mass in the hollow portion is not added to the vibrating mass, so that the vibration power can be reduced.

That is, in the case of the planar diaphragm shown in FIGS. 1 and 2, the hollow part of the hollow cone and the space formed around the outer periphery of the cone in the plate-like bases A and B are completely external. It is open to the world and connected to the outside world.

This means that unlike a conventional honeycomb core type planar diaphragm in which each core is formed of completely independently closed spaces, there is no room for air expansion within the core.

Therefore, there is no deformation damage to the plane diaphragm caused by this. Further, it is possible to generate sufficient sound with small vibration power without requiring vibration power due to the addition of air mass and vibration mass in the core.

In addition, in the case of the planar diaphragm shown in FIG. 3, the plate-like base 10
The part (I) corresponding to the hollow part of each hollow cone in is all open and connected to the outside, while the space (■) formed by the outer wall of the hollow cone is the sheet material 12 Due to the presence of , a common wide closed space is formed inside.

Therefore, unlike the conventional honeycomb core type planar diaphragm in which the inside of the core is completely independently closed, there is no risk of air expansion, and there is no need for large vibration power, but it can be handled with a sufficiently small vibration power. It is possible.

In the planar diaphragm having the configuration shown in FIG.
6 form independent closed spaces, but the outer circumferential space (TV) of the hollow cone forms a common wide-area closed space similarly to (II) in FIG. 3, and the honeycomb core Compared to the case of a flat type diaphragm, there are almost no troubles caused by air expansion, and it can be dealt with sufficiently with a small vibration power.

In the case of FIG. 5, portions (V) and (■) corresponding to the hollow portions of the hollow cone of the plate-like base 17, 18 are both open and connected to the outside.

On the other hand, in the outer circumferential space (■) of each hollow cone, a common wide space is maintained by both the plate-shaped bases 17 and 18 inside, and for the same reason as above, there is no trouble due to air expansion, and small vibration power is generated. sufficient effect can be achieved.

In addition, in the case of the configuration shown in FIG.
The parts (■) and (IX) corresponding to the hollow part of each hollow cone are both open and connected to the outside,
A space (X) and (
XI) also forms a separate and common wide closed space with the intermediate sheet material 25, so similarly there is no trouble caused by air expansion and no large vibration power is required.

〔Example〕

Hereinafter, this invention will be explained in more detail with reference to the drawings.

FIG. 1 is a perspective view showing the structure of a plate-like substrate corresponding to the core of the flat diaphragm of the present invention. It is composed of a shaped substrate A.

And each of these hollow quadrangular pyramids has a base of 2°2.2
It has a shape in which ... is cut out, and each top part 3.3.3...
・ are arranged on the same plane, and each of the four sides making up the bottom is joined to each side of an adjacent hollow square pyramid, and these are made from a single sheet-like object. It is molded.

FIG. 2 is a perspective view showing another structure of the plate-like base body corresponding to the core of the plane diaphragm according to the present invention, and the plane diaphragm is made up of a large number of hollow cones 4, 4, 4, . It is composed of plate-shaped substrates B that are bonded together.

Similarly, each of the hollow cones has a base of 5°5.5°.
It has a shape in which ... is cut out, and each top part 6.6.6.
... are arranged on the same plane, and each peripheral edge constituting the bottom is mutually joined to each peripheral edge of an adjacent hollow cone, and these are also in the form of a single sheet. It is molded from a material.

A plate-shaped base body having a shape obtained by joining together a large number of hollow cones as shown in Figs. However, as described above, it may be a molded product obtained by vacuum forming or press molding a single sheet-like product, or it may be a molded product obtained by cast molding. good.

There is no particular limit to the height h of the cone shown in FIGS. 1 and 2, but the higher the height h, the more rigid a plane diaphragm can be obtained, so this height should be taken into consideration. By molding a plate-like substrate in this manner, a planar diaphragm having arbitrary rigidity can be obtained.

Although such a plate-shaped substrate can be used directly as a flat diaphragm in a speaker or the like, it is preferable to use it in the manner described below in order to improve the strength and exhibit sufficient acoustic effects.

That is, the planar diaphragm shown in FIG. 3 is one in which each top portion 1) of a plate-shaped base 10 is commonly joined by one sheet material 12. As shown in FIG.

In addition, the planar diaphragm in FIG.
4 are jointed in common with one sheet material 15, and the part that constitutes the bottom of the hollow cone is joined with another sheet material 16.
These are commonly joined together.

The planar diaphragm shown in FIG. 5 has a shape in which a pair of plate-shaped substrates 17 and 18 are integrally joined at the tops 19 and 20 of each hollow cone.

The planar diaphragm shown in FIG. 6 is a pair of plate-shaped substrates 21 and 22, each of which is joined at its apex 23, 24 of each hollow cone through a single intermediate sheet material 25, thereby integrating the two.

By using a hollow cone, the planar diaphragm of the above embodiment has a hollow portion of the hollow cone and a space on the outer periphery of the hollow cone, which are significantly different from conventional honeycomb core type planar diaphragms. This completely eliminates troubles such as damage caused by air expansion inside the flat diaphragm.

Furthermore, since the air mass in the hollow portion is not added, the vibration power can also be reduced.

In each case a, as shown in FIG. 7, the tops of the hollow cones of the plate-shaped hollow body 26 are not kept sharp, but are flattened parallel to the bottom to form a flat surface portion 27. By forming this, the bonding with the sheet material or the bonding of each top portion can be ensured, and the strength of the planar diaphragm can be significantly improved.

The plate-like substrate in the flat diaphragm of this invention is paper.

Materials such as plastic films and metal plates can be used, and among them, paper is suitable for paper materials, polypropylene, polyethylene, etc. are suitable for plastic materials, and aluminum thin plates are suitable for metals.

As described above, these can be manufactured extremely easily by molding methods such as vacuum molding, press molding, and cast molding.

〔Effect of the invention〕

Since the plate-shaped substrate in the flat diaphragm of this invention is composed of a collection of many hollow cones, it has particularly excellent strength in the lateral direction of the plate surface. It has superior strength that is approximately equal to or surpasses that of a core-type flat diaphragm.

In addition, the plate-like base formed by a collection of many small cones has a high natural frequency because the cones are arranged obliquely to the plate surface of the flat diaphragm and act as a trumpet. can be generated.

In addition, each hollow part formed by a large number of such small cones and the space around the outer circumference of the cone eliminates complete isolation of the diaphragm from the outside world, and prevents deformation and damage of the diaphragm due to expansion of internal air. This prevents troubles and allows a planar diaphragm with a high frequency characteristic different from conventional planar diaphragms to be made with small vibration power.

The plate-like base, which forms the basis of the flat diaphragm in this invention, can be easily manufactured by simply molding a sheet-like material, and can be used as is or by joining other sheet materials to it. Since an excellent planar diaphragm can be obtained with just a few steps, manufacturing is extremely easy, and the present invention has great utility value in these respects.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing a plate-like base in a flat diaphragm of the present invention, FIG. 2 is a perspective view showing another aspect of the plate-like base, and FIG. 3 is a perspective view of a flat diaphragm of the present invention. FIG. 4 is a vertical cross-sectional view showing one aspect, and FIG.
The figure is also a longitudinal sectional view showing another embodiment, FIG. 6 is a longitudinal sectional view showing another embodiment, and FIG. 7 is a longitudinal sectional view showing another embodiment of the plate-like base in a plane diaphragm. . Code 1 in the drawing: Hollow square pyramid, 2.5: Bottom surface 3.6.1)
．． 14.19,20,23.24...top, 4...
Hollow cone, 12, 15.16...Sheet material, 25...Intermediate sheet material, 27...Flat surface portion Patent applicant NMB Audio Research Co., Ltd.

Claims (6)

[Claims] (1) A planar diaphragm comprising a plate-shaped base in which a large number of hollow cones with their bottoms cut out are connected adjacently to each other with their tops located on the same plane. (2) The planar diaphragm according to claim 1, wherein the plate-shaped base is formed by joining each top of the hollow cone with a common sheet material. (3) The planar diaphragm according to claim 1, wherein the plate-like base is formed by connecting the top and bottom portions of the hollow cone with a common sheet material. (4) The planar diaphragm according to claim 1, wherein the pair of plate-like bases are formed by joining the tops of hollow cones to form a single body. (5) Planar vibration according to claim 1, wherein the pair of plate-like bases is formed by integrally bonding the tops of each hollow cone through a common sheet material. Board. (6) The planar diaphragm according to any one of claims 1 to 5, wherein the hollow cone is flattened so that the top thereof is parallel to the bottom surface.