JPS5858877B2 - Vibrating body for acoustic transducer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a vibrating body for an acoustic transducer such as a diaphragm for a speaker or microphone or a cantilever for a record player cartridge. The Young's modulus E1 or the Young's modulus E and the density ρ of the vibrator material are permeated and diffused.
It relates to a high-performance vibrating body for acoustic transducers that has a high ratio of

Conventionally, the materials used for the above-mentioned vibrating bodies are often aluminum, titanium, etc., which are lightweight and easy to roll. A specific vibration mode is generated throughout the vibration system, causing a large peak in the high frequency response, which significantly impairs the sound quality.In the case of cantilevers for record player cartridges, the cantilever occupies most of the effective mass of the vibration system. However, it has been extremely difficult to reduce the effective mass of the vibration system required to improve the performance of the cartridge.

That is, if the thickness and diameter of the pipe are reduced in an attempt to reduce the weight of the cantilever, the rigidity decreases and the characteristics deteriorate.

To improve the above characteristics, the ratio of Young's modulus E to density ρ is E/
This can be achieved by using a material with a large value of ρ (hereinafter referred to as specific elastic modulus).

Materials with a large specific elastic modulus E/ρ include boron, beryllium, etc., but boron is difficult to obtain (particularly of high quality), and beryllium requires a large amount of money for pollution prevention equipment in the manufacturing process. I need.

In addition, materials with large E/ρ values such as boron and aluminum are generally difficult to process by rolling or pressing, and it requires a large amount of money to form into a predetermined shape, and the shape is also severely limited. It is something that will be done.

Therefore, a material that is easy to mold, such as aluminum or titanium, is molded into a predetermined shape, and a material with high E/ρ, such as boron or aluminum, is deposited by physical vapor deposition or using the molded material as a base. It is conceivable to obtain coated diaphragms, cantilevers, etc. by chemical vapor deposition or the like.

By the way, when forming a coating layer on a substrate by physical vapor deposition or chemical means, it is desirable to heat the substrate to 150°C or higher in order to improve the properties of the deposited film. Because the expansion coefficients differ greatly, mechanical distortion may occur after cooling, or cracks may appear in the coating layer, making it unusable.

It has also been proposed to provide a coating layer of beryllium or boron on the substrate by vapor deposition or the like, and then peel only this coating layer from the substrate to form a vibrating body made of only beryllium or boron. The aluminum or boron coating layer formed by this method has the disadvantage of having low mechanical strength and being easily broken.

Furthermore, in order to form a coating layer on a substrate by means such as vapor deposition, an evaporation device such as electron beam heating is required, which requires a large amount of equipment and takes a long time to manufacture, resulting in a very high product cost. .

Therefore, a vibrating body for an acoustic transducer has been proposed in which a diffusion region made of a diffusion material having different properties from that of the base body is formed on a base body that is to be a vibrating body for an acoustic transducer.

The present invention is directed to a vibrating body for an acoustic transducer in which a diffusion region made of a diffusion material is formed in a base, and its purpose is to:
Vanadium (V) and boron (B), which are suitable for this type of vibrating body, are selected as the base material and diffusion material, respectively, and the vibrating body in which the diffusion region is formed has the highest E/ρ.
An object of the present invention is to provide a vibrating body for an acoustic transducer having a high composition.

Hereinafter, the vibrating body for an acoustic transducer of the present invention will be explained with reference to the drawings.

FIG. 1 shows an embodiment in which the dome-shaped diaphragm of a speaker is applied as a vibrating body for an acoustic transducer in which a diffusion region is formed, and shows a cross-sectional view of the dome-shaped diaphragm which is a vibrating body according to the present invention. 1 is a substrate made of a thin plate of vanadium (V) alone or a compound mainly composed of vanadium (V) with a thickness of 25 μm, and formed by means such as pressing into a desired shape to become a dome-shaped diaphragm of a speaker. In this vanadium substrate 1, a boron (B) diffusion region A is formed over the entire surface of the vanadium substrate 1.

This diffusion region A contains vanadium (V) and boron (B).
), and its main component is vanadium disulfide (VB2).

In this way, a boron (B) diffusion region is formed in the vanadium substrate 1, and its main component is vanadium disulfide (VB).
2), other compounds of boron (B) and vanadium (V), namely trivanadium diboride (v
3. B2), vanadium boride (VB), vanadium tetraboride (VB, ), etc.
g-/7nd] and a particularly high Young's modulus E, it is possible to provide a high-performance vibrating body for an acoustic transducer.

Next, an embodiment of the method for manufacturing a vibrating body for an acoustic transducer according to the present invention will be described.

FIG. 2 is a cross-sectional view of a dome-shaped diaphragm showing the process of manufacturing the dome-shaped diaphragm of a speaker as a vibrating body according to the present invention, in which 1 is made of a vanadium (V) thin plate with a thickness of 25 mm. , is a base body formed by means such as pressing into a desired shape to become a dome-shaped diaphragm of a speaker, and a coating layer 2A of boron (B), which is a diffusion material, is deposited on both sides by means such as vapor deposition or coating. , 2B are formed.

In forming the coating layers 2A and 2B of boron (B) on the substrate 1 by coating means, boron (B) is ground into powder, and this powdered boron (B) is applied using the principle of electrostatic coating. Alternatively, it can be easily done by preparing a suspension of this powdered boron (B) in a highly volatile organic solvent such as trichloride or thinner and using a brush or spray. In this case, whichever method is used, the coating layers 2A and 2B formed on the substrate 1 are laminates of powdered boron (B) having a desired thickness.

Here, the powdery diffusion material has a diameter of 50 μm or less, preferably 10 μm or less, because the smaller the particle diameter, the larger the contact area with the small pillar base 1 and the easier diffusion. .

In addition, as a highly volatile organic solution for suspension, the solution is water (
Compared to substances with relatively low volatility such as B20), it has the effect of cleaning even if the substrate 1 is dirty to some extent and quickly vaporizing it.

Then, a coating layer 2A of boron (B) as a diffusion material
, 2B formed thereon is heated at a temperature of 1550° C. for 30 minutes to form a coating layer 2 within the substrate 1.
Introducing boron (B) formed as A, 2B,
A boron (B) diffusion region A is formed in the base 1.

After the desired heat treatment has been performed, the substrate 1 is cooled down to normal temperature (room temperature), and then a dome-shaped diaphragm for a speaker having a boron (B) diffusion region within the substrate 1 is obtained.

In the above-described embodiments of the present invention, the diaphragm for a dome-shaped speaker was explained as this type of oscillating body, but the diaphragm for a cone-shaped speaker, the diaphragm for a microphone, and the cantilever of a pickup cartridge may also be used. The present invention can also be applied to vibrating bodies for acoustic transducers such as There are cases where it is formed on the entire surface of the base 1 in the plane direction, and cases where it is formed on a part or portion thereof, depending on the desired purpose of the vibrating body for an acoustic transducer. It is enough if it is selected.

Furthermore, boron (B) is a diffusion material forming the diffusion region A.
In addition to the methods shown in the above examples, the application means include vapor deposition,
A method such as chemical vapor deposition may also be used.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a dome-shaped diaphragm of a speaker, which is a vibrating body for an acoustic transducer according to the present invention, and FIG. 2 shows a process for manufacturing the dome-shaped diaphragm of FIG. 1 according to the present invention. FIG. 3 is a cross-sectional view of a dome-shaped diaphragm. 1... Vanadium substrate, A... Boron diffusion region.

Claims (1)

[Claims] 1. In a vibrating body for an acoustic transducer, which is formed into a desired shape and is to become a vibrating body for an acoustic transducer, boron is impregnated into the base to form a boron diffusion region in the base, and the base is made of vanadium (V) or A vibrating body for an acoustic transducer, which is made of a compound containing vanadium as a main component, and has a diffusion region of diffused boron (B') containing vanadium disulfide (VB2) as a main component.