JPS5838038B2 - Cone-shaped honeycomb diaphragm - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cone-shaped honeycomb diaphragm for a speaker.

In general, the diaphragm of a speaker is lightweight and has a specific elastic modulus E/ρ(
E: Young's modulus, ρ: density) is required to be large and to have an appropriate internal loss tan δ.

In particular, in a cone-shaped diaphragm, the inner periphery (voice coil side) must faithfully propagate the vibrations of the coil bobbin, so a large specific modulus of elasticity is required, while the outer periphery (edge side) has a large specific modulus of elasticity. Since reflected vibrations must be absorbed, it is ideal that the internal loss tan δ is appropriately large.

However, E/ρ and tan δ are generally in an inversely proportional relationship, and when the skin material and composition are the same on both the inner and outer circumferences, as in the case of a conventional honeycomb-shaped diaphragm (Fig. 1), It is difficult to increase E/ρ at the inner circumference and tan δ at the outer circumference without increasing the total weight.
Therefore, it is impossible to sufficiently satisfy the required characteristics of the above-mentioned speaker diaphragm.

In order to improve the above-mentioned drawbacks of conventional products, the present invention relates to the skin material of a honeycomb-shaped diaphragm, and uses a material with a large E/ρ for the inner periphery, and a material with a relatively large tan δ for the outer periphery. That is.

For example, a CFRP (carbon fiber reinforced plastic) sheet is used for the inner periphery, which is required to be lightweight and have a large E/ρ, and a single synthetic resin sheet is used for the outer periphery.
FRP reinforced with natural or synthetic fibers that are lightweight and have a relatively large tan δ. Alternatively, paper can be used.

In order to manufacture the cone-shaped honeycomb-shaped diaphragm according to the present invention, skin materials made of different materials or compositions may be bonded to the inner and outer peripheral portions as shown in FIG. 2, or skin materials made of different materials or compositions may be used, or We made FRP sheets with different amounts of reinforcing fibers and materials, and used these sheets to create areas with a large E/ρ on the inner periphery and areas with a large E/ρ on the outer periphery, as shown in Figure 4. This is possible by constructing a portion with a large tan δ.

Figure 5 shows glass fibers. The fiber/epoxy resin volume ratio is 0.
A conventional cone-shaped honeycomb-shaped diaphragm using a skin material made of a sheet uniformly distributed and hardened so that the glass fiber/epoxy resin in the inner and outer peripheral parts is 0.30 in the inner and outer peripheral parts, respectively. , 0.05 (volume ratio) was used as the skin material for a cone-shaped honeycomb-shaped diaphragm.

As is clear from FIG. 5, the diaphragm according to the present invention has smaller peaks and dips in the high frequency range, as shown by the broken line 9 in FIG. 5, compared to the characteristic 8 of the conventional product, and has excellent acoustic characteristics. .

As described above, in the present invention, the material or composition of the skin material is different between the inner circumference and the outer circumference, the inner circumference is made of a material or composition with a large E/ρ, and the outer circumference is made of a material or composition with a relatively large tan δ. The present invention provides a cone-shaped honeycomb-shaped diaphragm with excellent acoustic characteristics by using a skin material of the same composition.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a conventional cone-shaped honeycomb diaphragm, FIG. 2 is a sectional view of a cone-shaped honeycomb diaphragm according to an embodiment of the present invention, and FIG. 3 is a sectional view of a skin material according to another embodiment of the present invention. An enlarged cross-sectional view, FIG. 4 is a cross-sectional view of a cone-shaped honeycomb diaphragm according to another embodiment of the present invention, and FIG. 5 is a sound pressure frequency characteristic. In the figure, 2 is the core of the honeycomb-shaped diaphragm, 3, 4, 7
5 is a skin material, 5 is a reinforcing fiber, and 6 is a resin layer.

Claims (1)

[Claims] 1. A cone-shaped honeycomb-shaped diaphragm characterized in that the inner peripheral part uses a skin material made of a material or composition having a large specific elastic modulus E/ρ, and the outer peripheral part uses a skin material made of a material or composition having a large internal loss tan δ.