JPS6237879B2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention uses a material with a high sound velocity as the diaphragm material and adds a material with a large loss around it, so that flat frequency characteristics can be obtained up to a high frequency band. This relates to a diaphragm made of

In general, the diaphragm of a speaker should be made of a lightweight material with a high sound velocity in order to widen the reproduction band, and should also have sufficient loss to obtain flat characteristics over the entire band. desirable. However, since there is no material that has such a high sound speed and sufficient loss, there is a problem in that only sound pressure characteristics with resonance peaks in the high range can be obtained, as shown by the solid line in FIG.

The present invention provides a diaphragm that solves these conventional problems, and provides a diaphragm that can obtain flat characteristics over a wide band and is easy to manufacture. be.

FIG. 1 shows an example devised during the process of completing the present invention. A core material 1 having a so-called honeycomb structure having a large number of cells has a surface material 2 on both sides thereof.
3 to form the diaphragm 4, and the surface materials 2, 3
The ends of the tape are extended, and a material with a large loss such as butyl rubber, semi-cured viscous rubber, or semi-cured adhesive sheet is sandwiched between them by a method such as gluing.

In this way, the sound velocity of the diaphragm 4 itself is high, and at the same time the loss around it becomes large, so the loss of the diaphragm 4 also becomes equivalently large, and as a result, as shown by the broken line in FIG. A flat sound pressure characteristic can be obtained.

In FIG. 2, the peripheral portion of the core material 1 is replaced with a material 6 having a large loss. In this case, if heat-adhesive foam rubber or the like is used as the material 6, the material 6 will be adhered to the surface materials 2 and 3 when forming the diaphragm 4, and if the core material 1 is a honeycomb, the cut end of the honeycomb will also be bonded. Since it is bonded to the material 6, it is easy to manufacture the diaphragm 4, and there is no cracking phenomenon caused by the edges of the honeycomb, and furthermore, by using the foam material, a lightweight diaphragm can be made while maintaining a large loss. I can do it.

FIG. 3 shows an increase in the loss of the diaphragm 4 and a connection with the edge 7 by configuring the edge 7 with a material with high loss and sandwiching a part of the edge 7 between the ends of the surface materials 2 and 3. It is designed to simultaneously realize the following.

FIG. 4 shows a structure in which a material 5 with a large loss is provided around the core material 1, and this material 5 is provided between the ends of the surface materials 2 and 3, thereby damping the space between the surface materials 2 and 3. It was designed to do so. If this is done, an effect equivalent to the combination of those shown in FIGS. 1 and 2 can be expected.

In FIG. 5, the peripheries of the surface materials 2 and 3 are further constructed with curved surfaces. As shown in Figures 1 to 4,
If the peripheries of the surface materials 2 and 3 are bent, some of the longitudinal waves of the surface materials 2 and 3 will be reflected at the bent portions, making it impossible to absorb the longitudinal waves sufficiently. On the other hand, if it is constructed with a curved surface as shown in FIG. 5, the reflection of longitudinal waves will be reduced, so that the longitudinal waves will be sufficiently absorbed, and the reflection can be increased accordingly.

FIG. 6 shows an embodiment of the present invention, in which an edge 7 is integrally formed with the material 5 shown in FIG.
If the material 5 with a large loss and the edge 7 are integrally formed in this way, manufacturing is easy, and the surface material 2,
The peripheral portion of the diaphragm 3 is squeezed to provide a narrow portion, and the narrow portion can be configured to hold the material with a large loss formed integrally with the edge 7, and the edge can be strongly attached to the diaphragm.

It goes without saying that corrugation or the like may be used as the core material other than honeycomb.

As described above, the present invention increases the loss of the diaphragm by adding a high-loss material around the lightweight diaphragm, so that the sound pressure characteristics are made flat over a wide band. In addition, it is possible to form the edge with a material with large loss in one piece,
In addition, since the material with a large loss is held between the narrow portions formed around the periphery of the surface material, manufacturing and assembly can be performed extremely easily, and the material with a large loss can be reliably fixed at the correct position on the diaphragm. I can do it.

[Brief explanation of the drawing]

Figures 1 to 5 are half-sectional views of a diaphragm conceived in the process of completing the present invention, Figure 6 is a half-sectional view of a diaphragm according to an embodiment of the present invention, and Figure 7 is a half-sectional view of a diaphragm according to an embodiment of the present invention. It is a characteristic diagram. 1... Core material, 2, 3... Surface material, 4... Vibration plate, 5, 6... Material with large loss, 7... Edge.

Claims (1)

[Claims] 1. A surface material having a narrow portion attached to both the front and back sides of a core material and formed by squeezing the peripheral portion, a material with a large loss provided on the peripheral portion of the core material, and a material with a large loss formed integrally with the material with a large loss. 1. A diaphragm comprising a formed edge, wherein the material with a large loss and an end of the edge are clamped and fixed in a narrow part of the surface material.