JPS5832387Y2 - vibrating body - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to the structure of a vibrating body used in a speaker or the like.

Generally, in a speaker, in order to support the diaphragm on a frame, the peripheral portion of the diaphragm is supported via an edge.

As such edges, conventionally known are a free edge in which a diaphragm and an edge are separately bonded together, and a fixed edge in which a diaphragm and an edge are integrally structured.

The material for the edge in the free edge is selected from materials having appropriate elasticity and flexibility as a support, such as resin foam, cloth damping agent, plastic film, and the like.

On the other hand, as the material for the diaphragm, a material with a large E/ρ (inelastic strength) such as paper, metal, resin, or composite material is selected.

The acoustic and auditory characteristics of a diaphragm are determined by the shape and material of the diaphragm.In particular, the material selected is one with low density and high rigidity, which causes sudden peaks and dips during split resonance. In addition, a sharp peak occurs at a high resonance frequency, producing a unique sound (coloration), and the resolution becomes noticeably rough, making it unpleasant to the ear.

Conventionally, various methods have been used to solve these problems, such as providing the diaphragm with an appropriate internal loss or providing a secondary damping substance.

Furthermore, with this free edge, the influence of the adhesive used to bond the diaphragm and edge together is significant.

On the other hand, in a fixed edge, the material of the diaphragm must also function as an edge, so a material with low compliance is selected.

This causes problems such as an increase in the low-frequency resonant frequency, an increase in distortion from low amplitudes, and a tendency for valleys to appear in the mid-range.

The present invention provides a vibrating body that solves the above-mentioned problems of free edge diaphragms and fixed edge diaphragms, and has high inelastic strength on both sides of the vibration surface of the diaphragm with fixed edges. It is covered with material.

Embodiments in which the present invention is applied to a speaker will be described below with reference to the drawings.

FIG. 1 shows the principle of the present invention when applied to a cone-shaped speaker.

The basic structure of this vibrating body 1 is that skin materials 4 and 5 are attached to the front and back surfaces of the vibrating surface of a cone-shaped core material 3 in which an edge 2 is integrally provided, and this vibrating surface has a sandwich structure. There is.

In the figure, 6 is a voice coil, and 7 is a coil bobbin.

Examples of the core material 3 include urethane, vinyl chloride, ethylene-vinyl acetate copolymer, olefin resin, rubber resin foam, cotton, natural fiber, synthetic fiber cloth, rubber fiber, elastomer, terrax, etc. with added damping agent, and nylon, plasticized vinyl chloride acetate, DAC, TA
A material such as C, which has appropriate elasticity and flexibility, and has a large internal loss is selected.

Further, as the skin materials 4 and 5, a metal that is lightweight and has a high elastic modulus, such as aluminum, beryllium, titanium, magnesium, etc., is selected.

As a method of adhering the core material 3 and the skin materials 4 and 5, the following method may be mentioned.

(1) The core material 3 and the skin materials 4 and 5 are directly thermocompressed or self-fused.

Since this method does not use adhesive, the weight of the vibrating body 1 can be reduced.

(3) When a foam is used as the core material 3, the edges 2 are sealed, and this sealing agent can be effectively used as an adhesive.

(3) Apply a heat-sealing type anchor coat to the surface of the core material 3 or the skin materials 4 and 5 in advance.

Next, a specific example of the method for manufacturing the vibrating body 1 will be described.

Young's modulus as core material 3: 6 x 106 N/m2. density:
300 g/m3. Internal loss: A urethane foam with tan δ = 0.17 is used and semi-heat pressed to a thickness of 0.5 mm or less.

In addition, as the skin materials 4 and 5, aluminum foil with a thickness of about 50 μm is used, and a polyimide heat-sealing adhesive is applied to this in advance to a thickness of 1 μm.
Anchor coat with 0-20μ.

Layer this aluminum foil on the front and back sides of the core material 3,
The vibrating body 1 is heat-pressed at 80°C for about 1 minute.
can be obtained.

Furthermore, when press molding the urethane foam, aluminum foil may be stacked together and molded at the same time.

According to the above-mentioned vibrating body 1, the above-mentioned problem that occurred due to the low density and high rigidity of the conventional free edge diaphragm can be solved.
This can be improved by providing internal loss with the core material 3.

In addition, the above-mentioned problem caused by the low compliance of the fixed edge diaphragm can be improved by reinforcing both sides of the core material 3 with the skin materials 4 and 5. It is possible to obtain a vibrating body that has both advantages.

FIGS. 2A and 2B show an embodiment of the present invention.

In the vibrating body 1 diaphragm shown in FIG. 1 described above, the vibration waves transmitted from the voice coil and the vibration waves reflected at the edges collide near the boundary between the edge and the vibration surface.
A vibration wave node occurs near this area, which causes a trough to occur in the midrange.

This embodiment solves this problem by making the skin material 4 or 5 near the edge 2 of the vibrating body 1 shorter by a length l than the other, as shown in FIGS. 2A and 2B. Sa l
This part has a Kanatsupe structure.

By forming the canope structure near the edge 2 in this way, the way vibration waves propagate changes in this area, so the generation of nodes of vibration waves can be suppressed, and troughs in the midrange can be suppressed.

The present invention includes a core material 3 having a cone shape, an edge portion integrally formed around the periphery, and made of a material having a predetermined inelastic strength and internal loss; A low-density, high-rigidity metal layer 4 or 5 is laminated on a portion of one surface excluding the edge portion, and a metal layer 4 or 5 of low density and high rigidity is laminated on a portion of the other surface excluding the edge portion and a portion up to a predetermined distance l from the edge portion. This relates to a vibrating body comprising the above-mentioned low-density and high-rigidity metal layer 5 or 4.

Therefore, according to the present invention, the above-mentioned problems in the conventional free edge and fixed edge can be solved, and a vibrating body with high internal loss while having high rigidity can be obtained.

It is also possible to suppress the occurrence of nodes of vibration waves and eliminate the occurrence of valleys in the midrange.

[Brief Description of the Drawings] Fig. 1 is a partial perspective view of a vibrating body showing the principle of the present invention when applied to a cone-shaped speaker, and Fig. 2 is a perspective view of essential parts showing an embodiment of the present invention. It is. In addition, in the symbols used in the drawings, 1...
- Vibrating body, 2... edge, 3... core material, 4, 5... skin material.

Claims (1)

[Scope of utility model registration request] A core material having a cone shape, an edge portion integrally formed around the periphery, and made of a material having predetermined inelastic strength and internal loss, and one of the front and back surfaces of the core material. A low-density, high-rigidity metal layer laminated on a portion excluding the edge portion, and a low-density, high-rigidity metal layer laminated on a portion of the other surface excluding the edge portion and a portion up to a predetermined distance from the edge portion. A vibrating body consisting of a metal layer.