JPH06101874B2 - Horn for speaker - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a speaker horn having excellent vibration damping properties and preferably having high elasticity.

Generally, a speaker horn is required to have a vibration damping property in order to suppress resonance at a specific frequency, and preferably the specific resonance frequency is shifted to a higher frequency range,
High elasticity is required to reduce adverse effects on sound quality.

Conventional speaker horn materials include (a) wood (simple or plywood) (b) metals such as zinc, aluminum, or their alloys (c) vinyl chloride resin, thermoplastic resin such as ABS resin, phenolic resin, Thermosetting resin such as epoxy resin is used.

The materials of (a) and (b) above have higher elasticity than (c), but since the loss coefficient is small and the damping property is insufficient, a so-called viscoelastic substance such as butyl rubber is attached to the horn surface. Although deadening is being performed, sufficient damping effect cannot be obtained. The materials of (c) above have a larger loss coefficient than those of (a) and (b), but they are still insufficient, and both materials have the drawback of being inferior in terms of vibration damping property.

An object of the present invention is to provide a speaker horn having excellent vibration damping property and preferably having high elasticity.

The speaker horn of the present invention comprises a horn base material 1a and a damping material 2 newly developed as an acoustic material laminated on the horn base material 1a.
It is characterized by having a three-layer structure in which the restraint member 1b is laminated on it.

In the present invention, the damping material 2 in the middle is deformed by the vibration of the horn base material 1a, the vibration energy is converted into heat energy and dissipated, and the vibration is damped to improve the vibration damping property. Is. That is, in the three-layer structure of the present invention, since the surface of the vibration damping 2 laminated on the horn base material 1a opposite to the laminated surface with the horn base material 1a is constrained by the constraining member 1b, When the vibration damping material 2 is deformed due to the vibration of the base material 1a, the amount of deformation of the vibration damping property 2 is increased, and the effective vibration damping property is obtained.

The horn substrate in the present invention includes wood (simple or plywood), thermoplastic resin, thermosetting resin, and preferably metal such as zinc, aluminum or alloys thereof having higher elasticity than these materials, high elasticity High elastic fiber reinforced synthetic resin in which a thermosetting resin is laminated in a predetermined shape using fibers as a reinforcing material, a liquid thermosetting resin in which a fine particle filler and an aggregate are mixed is molded and hardened into a predetermined shape, so-called There is resin concrete.

The horn substrate made of the high-elasticity fiber-reinforced synthetic resin has a horn-shaped woven or non-woven fabric of high-elasticity fiber laid on it, and is impregnated with a mixed liquid of a thermosetting resin, a catalyst and an accelerator to form a first layer. And laying a woven or non-woven fabric of high elastic fiber on the first layer, impregnating this with a mixed liquid of thermosetting resin, catalyst and accelerator to form the second layer, and so on. Is repeated to laminate in multiple layers. Highly elastic fibers include glass fibers, carbon fibers, silicon carbide fibers, alumina fibers, boron / tungsten fibers, aromatic polyamide fibers (aramid fibers), and the like.
Examples of thermosetting resins include unsaturated polyester resins, epoxy resins, and phenol resins.

The resin concrete horn base material was added with a mixture of a thermosetting resin, a curing catalyst added as necessary, and an accelerator, a fine particle filler and an aggregate (gravel, fine sand, etc.) and sufficiently stirred. After that, fill the horn mold (driving method) or apply iron to the male face of the horn, and after curing,
It was taken from the mold. As a fine particle filler,
There are fine powders of emery, alumina, silica stone, quartz, etc., silicon carbide powder, calcium carbonate powder, slate powder, iron oxide powder, etc. Also, as thermosetting resin, unsaturated polyester resin, epoxy resin, phenol Resin etc.

The following table shows typical examples of Young's modulus and loss coefficient of each horn substrate as described above.

Examples of the restraint material in the present invention include an iron plate, an aluminum plate, wood (a single plate or plywood), a synthetic resin plate, a highly elastic fiber-reinforced synthetic resin plate, and a resin concrete plate.

As the damping material in the present invention, nitrile-butadiene copolymer, styrene-butadiene copolymer, butyl rubber, neoprene, those containing rubber such as urethane as a main component, or vinyl chloride, vinyl chloride-vinyl acetate copolymer Some have a thermoplastic resin such as a polymer, vinyl acetate or ethylene-vinyl acetate copolymer as a main component, and further have a thermosetting resin such as an epoxy resin, a polyester resin or a phenol resin as a main component. Preferably, these viscoelastic substances themselves have a large loss factor, such as nitrile-butadiene copolymer, butyl rubber, vinyl chloride, vinyl chloride-vinyl acetate copolymer, unsaturated polyester resin, rubber or resin such as vinyl ester. Is a vibration-damping material whose main component is or a vibration-damping material whose main component is a mixture of these rubbers or resins. Masui.

A filler can be contained in these main components as a means for increasing energy loss due to internal friction with the main component viscoelastic substance and increasing the loss coefficient. Flake-shaped mica, graphite, carbon black, magnesium oxide, zinc white, etc. having a large contact interface with is desirable.

Further, in consideration of the workability of the viscoelastic substance and the temperature characteristics of the loss coefficient, it is necessary to add a plasticizer, a softening agent or the like.

Hereinafter, examples of the present invention will be specifically described.

Each of the blends blended in the blending ratio shown in Table 1 was formed into a sheet and pressed under the following conditions to obtain a sheet-shaped damping material having a thickness of 3 mm. This sheet damping material is 10 mm wide and 150 mm long
After cutting into pieces, the loss coefficient tan δ at 25 ° C and 500 Hz was obtained by the vibration lead method.

Press conditions Damping material A 120 ℃ × 10 minutes (water cooling after press) Damping material B 140 ℃ × 30 minutes Damping material C 160 ℃ × 60 minutes Damping material D 150 ℃ × 10 minutes (Note) 1. Vibration damping Agent A Plasticizer: Dioctyl phthalate Stabilizer: Epoxidized soybean oil 2. Damper C Vulcanizing agent: phenol formaldehyde resin 3. Damper D Curing catalyst: benzoyl peroxide [Example 1] As shown in Fig. 2, in a glass fiber reinforced synthetic resin horn (1), a sheet-like vibration damping material (2) (vibration damping material B) having a thickness of 3 mm was used as an intermediate layer during horn molding. Embedded as a three-layer structure. That is, the horn base material and the restraint material were made of the same material, glass fiber reinforced synthetic resin.

Here, the dimensions of each part of the horn are the opening part (inner diameter) of the horn 550 mm × 300 mm, the throat part of the horn (inner diameter) 184 mm × 184 mm, the horn length 200 mm, and the thickness of the inner and outer layers of the horn 5 mm (each layer is 6 layers).

[Example 2] A horn having the same size as that of Example 1 was used for lauan plywood (horn base material).
The sheet-shaped damping material was attached to the upper, lower, left, and right outer surfaces, and the iron plate (restraining material) was attached on it.

The thickness of the horn, sheet damping material, and iron plate is 20 mm,
3 mm and 0.8 mm.

[Example 3] Sheet-shaped damping materials were attached to the top, bottom, left and right outer surfaces of the (horn base material) of a zinc horn having the same dimensions as in Example 1, and iron plates (restraining materials) were attached thereon.

The thickness of the horn, sheet damping material, and iron plate are 5 mm and 3 respectively.
mm and 0.8 mm.

In addition, in Example 2 and Example 3, the same damping material B as in Example 1 was used.

Samples (width 10 mm, length 150 mm) in each of the above examples
The Young's modulus and loss coefficient of were measured by the vibration lead method and were as shown below. (See P-6 for comparative examples) As described above, the present invention is composed of a three-layer structure in which a vibration damping material newly developed as an acoustic material is laminated on a horn base material, and a restraining material is laminated on the vibration damping material. It is possible to provide a horn for a speaker having.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a view showing the structure of a speaker horn of the present invention,
FIG. 2 is a structural diagram showing the partially cutaway surface of another embodiment of the present invention.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Takashi Shiono, 2-1, Nisshincho, Neyagawa-shi, Osaka Prefecture Onkyo Corporation (72) Inventor, Akira Yasue 2-1-1, Nisshincho, Neyagawa City, Osaka Prefecture Onkyo Corporation (72) Inventor Hajime Imada 2-1, Nisshin-cho, Neyagawa-shi, Osaka Onkyo Co., Ltd. (72) Inventor Hideo Kikuchi 918-53 Tanaka, Nakai-cho, Ashigagami-gun, Kanagawa Kenji Yamashita (56) References Showa 49-14431 (JP, U) Actually opened Showa 57-7283 (JP, U)

Claims (3)

[Claims] 1. A horn base material having a temperature of 25 ° C. and a vibration frequency of 500 H.
Formed in the form of a sheet containing a rubber, a thermoplastic resin or a thermosetting resin, or a mixture of two or more of a rubber, a thermoplastic resin or a thermosetting resin, having a loss coefficient (tan δ) at z of 0.2 or more as a main component. A speaker horn having a three-layer structure in which a damping material is laminated, and a restraint material is further laminated on the sheet-shaped damping material, wherein the rubber of the damping material is a nitrile-butadiene The thermoplastic resin is a vinyl-based polymer such as vinyl chloride, vinyl chloride-vinyl acetate copolymer, vinyl acetate or ethylene-vinyl acetate copolymer. A speaker horn made of a polymer or a vinyl copolymer, wherein the thermosetting resin is an epoxy resin, a polyester resin, or a phenol resin. 2. The speaker horn according to claim 1, wherein the horn base material and the restraint material are the same material. 3. The speaker horn according to claim 1 or 2, wherein the horn base material and the restraint material are glass fiber reinforced synthetic resins.