JPS61148998A - Loudspeaker diaphragm - Google Patents

Abstract

PURPOSE:To obtain the titled diaphragm light in weight with high rigidity by forming the diaphragm body with a simple substance of light metal or its alloy to form a coating layer on the body and uniformly disperse needle-form crystal in the coating layer. CONSTITUTION:A diaphragm plate 1 is formed by a diaphragm plate body 1a made, for instance, of aluminum Al of purity of 99.9% as a light metal simple substance and the coating layer 1b coated on the front and back surfaces of this diaphragm body 1a. In the coating layer 1b, the silicon carbide whiskers 2 whose diameter and length are approximately 0.05-0.2mu and 10-40mu respectively are uniformly dispersed and deposited in the Ni-P that is a matrix material 3. As a result, the diaphragm thus made is lighter in comparison with a metal diaphragm of such as titanium, and possesses higher regidity in comparison with the one formed by aluminum, and accordingly obtains a faster propagation speed. The diaphragm, also, is able to propagate a higher harmonic frequency. Therefore, the acoustic characteristic is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field of the Invention) The present invention relates to a speaker diaphragm that is lightweight, has high rigidity, and has improved durability.

(Technical background of the invention and its problems) The following points are required for a diaphragm for a speaker, microphone, etc.: (a) mass ρ is small and lightweight; (b1 elastic modulus E is large; (C) High rigidity and moderate internal loss.

Conventionally, the diaphragm has been formed of paper, synthetic resin, metal, etc., as long as these conditions are satisfied. Although these materials satisfy the above items (a) to (C), each has advantages and disadvantages when formed alone, and most of them are mixed with other materials or formed as a composite. There is.

In particular, dome-shaped diaphragms have been used in high-frequency speakers that reproduce high-frequency ranges to improve directivity, but conventionally, these diaphragms were made of metal materials such as aluminum and titanium that are easy to process. It was molded. Diaphragms molded from these materials are effective in raising the treble reproduction limit frequency and strongly exhibit the characteristics of metal diaphragms, but they also exhibit the advantages and characteristics of other materials other than metal. I couldn't do that.

As a metal diaphragm, one using beryllium is lightweight, has a large elastic modulus E, and a large specific elastic modulus %, and is the best molding material for electroacoustic transducer diaphragms, but it is brittle and difficult to manufacture. It had the disadvantage of being expensive. That is, press-molding of dome-shaped diaphragms using beryllium has been limited to those with dome diameters of 40 to 50 m or less. For this reason, in order to manufacture a dome-shaped diaphragm of larger size using beryllium, the general method has been to manufacture the diaphragm by vacuum deposition. There are currently two specific methods in this case:

That is, one method is to first mold a dome-shaped diaphragm main body using aluminum foil, and then layer beryllium on the top surface of this diaphragm main body by vacuum evaporation, thereby creating a composite material of aluminum and beryllium. It formed a diaphragm.

The second method is to mold the adhesive body using copper foil, layer beryllium on the top surface of the adhesive body using a vacuum evaporation method, and then remove the copper foil by etching it with a chemical such as nitric acid. By this process, a diaphragm made of beryllium is manufactured.

However, among the above methods, the former has the advantage that it can be manufactured at a lower cost than the latter, but on the other hand, it has the disadvantage that the physical properties of the aluminum from which the diaphragm is mainly manufactured are greatly affected, and the original physical properties of beryllium are impaired. There is.

The latter method has the advantage of obtaining beryllium's original physical properties, but it requires forming a thin film as a diaphragm using only beryllium metal, and it also requires a secondary process called etching, which increases the number of steps. This has the disadvantage that the cost of the diaphragm as a product becomes considerably high.

(Objective of the Invention) The present invention has been made in view of the above-mentioned points, and its purpose is to provide lightweight and high rigidity, easy manufacturing without any restrictions on processing, and low cost. The purpose is to provide an inexpensive speaker diaphragm.

(Embodiments of the Invention) The present invention will be described below with reference to the drawings, using a speaker imaging plate as an embodiment.

1 is a diaphragm, and this diaphragm 1 includes a diaphragm main body 1a molded from 99.9% pure aluminum (/l) as a light metal, and a coating on the front and back surfaces of this diaphragm main body 1a. It is formed from the plating layer 1b. In this mesh layer 1b, carbide silica whiskers 2 having a diameter of, for example, 0.05 to 0.2μ and a length of about 10 to 40μ are uniformly dispersed and precipitated in N1-P as the matrix material 3. ing.

To form the plating layer 1b on the main body 1a of the diaphragm, for example, steam using trichlorethylene, degreasing, and HN O
3. Pickling treatment using an oxidizing agent such as HF, water washing treatment J Each process such as zinc substitution to activate the substrate surface and water washing treatment is repeated at least twice to give sufficient strength to the vibrating electrode substrate 1a. ti44 = Ni:P blending ratio is 90-92:8-10 after passing through a pretreatment process consisting of cleaning and activation
Add 20tmt of SiC to the (wt%) mixture.
N1 as a matrix material is applied to the front and back surfaces of the diaphragm main body 1a molded from aluminum by heating it at a temperature of 90 to 95°C and exposing it to a plating solution containing a mixture of approximately
- A plating layer 1b having a thickness of about 2 microns is coated with silica carbide whiskers 3 having a diameter of 0.05 to 0.2 microns and a length of about 10 to 40 microns uniformly dispersed and precipitated in -P.

A practical example of the present invention has the above-mentioned configuration, and has a diameter of 0 in N1-P as a matrix material on the front or back surface of the diaphragm main body 1a molded from aluminum as a light metal.
．． The diaphragm 1 of this embodiment has a plated layer 1b formed by uniformly dispersing and precipitating siliceous carbide whiskers 3 having a size of 05 to 0.2μ and a length of 10 to 40μ, and a purity of 99.9.
The following table (1) was obtained by comparing the physical properties such as density ρ, elastic modulus E, specific elastic modulus, etc. of conventional diaphragms of this kind manufactured using aluminum foil of 20%.

Table 1 As is clear from the above table (I), the diaphragm 1 of this example
Among the physical properties, the density ρ is 2' and 4' for conventional diaphragms molded from 99.9% pure aluminum or titanium, respectively, whereas the density ρ is 2' for diaphragms formed using metal. It is lightweight for a diaphragm that does this. Also, the elastic modulus E of the conventional vibrator made of aluminum is 72 x l Q
11, whereas in this example it is 12'X10"←
/crl and high. Therefore, the rigidity of the conventional diaphragm main body 1a, which is molded from aluminum, has N1-P as a matrix material with silica carbide whiskers with a diameter of 0.05 to 0.2μ and a length of 10 to 40μ. 3
This is because the plated layer 1b is coated with the plating layer 1b, which is uniformly dispersed and precipitated.

Further, since the plating layer 1b is coated on the diaphragm main body 1a through the relatively simple process described above, manufacturing and processing are easy.

In the above embodiment, the diaphragm main body 1a is molded from aluminum, which is a light metal, but it may also be molded from other alloys, or may be formed into a cone shape instead of a dome shape. In the above embodiment, N1-P is used as the matrix material 3 constituting the plating layer ib, but other metals such as Ni, Co, Cu, and Cr and binary alloys such as Ni-3 and Ni- Co, Ni-Mn, Ni-
Cr, Ni-Mo, Co-W, Fe-Cr, Ni-B
etc. is also fine. Further, as the needle-shaped crystals dispersed in the matrix material 3, silica carbide whiskers 3 are used in the above embodiment, but other needle-shaped crystals such as nitride silica whiskers and poron whiskers may also be used. .

(Effects of the Invention) As described above, the present invention molds the main body of the diaphragm from a light metal such as aluminum or an alloy thereof, and has needles such as silica carbide whiskers, silica nitride whiskers, and boron whiskers on the front and back surfaces of the diaphragm. Since it is coated with a plating layer in which crystals are dispersed in the matrix material, it is lighter compared to metal diaphragms such as titanium, and has higher rigidity than metal diaphragms such as aluminum, resulting in faster propagation speed. This allows higher-order frequencies to propagate and improves acoustic characteristics.

Moreover, manufacturing and processing are easier than when beryllium is used, and costs are lower.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing one embodiment of the present invention, and FIG.
FIG. 2 is an enlarged cross-sectional view of circle A in the figure. DESCRIPTION OF SYMBOLS 1... Diaphragm, 1a... Diaphragm main body, lb... Plating layer, 2... Matrix material, 3... Silica carbide whiskers. Patent Applicant: Pioneer Co., Ltd. Procedural Amendment (Voluntary) July 8, 1985, Mr. Uga Michibu of the Demand Agency, 1, Indication of Case: 1980 Patent Interchange No. 27
0638 No. 2, Title of the invention Speaker diaphragm 3, Distance from the person making the correction Patent applicant address 1-4-1 Meguro, Meguro-ku, Tokyo Name (501)
) Pioneer Co., Ltd. 4, Agent 5, Date of amendment order: Showa year, month, day Contents of amendment (Patent Application No. 59-270638) 1, Specification,
On page 6, line 13, "open dipping" is written as "intermittent dipping".
Correct to. 2. Table I on page 7 of the specification is amended as follows. Notation ■3. In the specification, page 8, line 1, the descriptions of r2', 4'J are corrected to r2.7, 4.5J. 4. In the specification, page 8, line 2, the description "r 29J" is corrected to r2.95J. 5. In the specification, page 8, line 4 says "72".
7.2 Correct to J. 6. The statement r12'J on page 8, line 5 of the specification is corrected to r12.4J.

Claims (6)

[Claims] (1) A speaker characterized in that the main body of the diaphragm is molded from a light metal or an alloy thereof, a plating layer is formed on the surface of the main part of the diaphragm, and acicular crystals are uniformly dispersed in the plating layer. diaphragm for use. (2) The speaker diaphragm according to claim 1, wherein the diaphragm is mainly made of aluminum or a metal alloy thereof. (3) The diaphragm for a speaker according to claim 1, wherein the needle-like crystals are silica carbide whiskers. (4) The speaker diaphragm according to claim 1, wherein the needle-like crystals are nitrided silica whiskers. (5) The speaker diaphragm according to claim 1, wherein the needle-like crystals are boron whiskers. (6) The speaker diaphragm according to claim 1, wherein the needle-like crystal is made of ceramic.