JPS5837184Y2 - Coaxial flat speaker diaphragm - Google Patents

Description

[Detailed description of the invention] The present invention relates to a diaphragm having an annular and flat honeycomb sandwich structure.The node of the first resonance mode of this diaphragm is a perfect circle, and the radius of the circle is The aim is to obtain a speaker diaphragm that is small in size and suitable for nodal drive.

A coaxial speaker, which has multiple speakers arranged coaxially, is
This has the advantage that the position of the sound source does not change depending on the frequency.

However, conventional coaxial speakers with cone-shaped diaphragms have complicated baffle shapes, making it impossible to obtain flat sound pressure characteristics.

Therefore, it is necessary that the bass diaphragm has a planar shape.

Recently, honeycomb sandwich structure diaphragms have attracted attention as lightweight and highly rigid flat diaphragms, and it has become possible to produce flat and annular diaphragms.

FIG. 1 shows a sectional view of a coaxial speaker using an annular flat plate diaphragm 1 as a bass reproduction diaphragm.

A treble speaker 2 is arranged in the hollow part of the annular flat plate diaphragm 1.

Further, the voice coil 3, whose first resonance mode of the diaphragm is shown by a broken line in the figure, is bonded and driven at a node where the diaphragm does not vibrate, thereby expanding the reproduction band.

FIG. 2 also shows a cross-sectional view of a coaxial speaker having an annular flat plate diaphragm 1 similar to that in FIG.
The node of the first resonance mode of the diaphragm is driven through the diaphragm.

In both figures, 5 and 6 are free edges, 7 is a magnetic circuit,
8 is a frame.

FIG. 3 shows the shape of a core material 1' having a conventional honeycomb sandwich structure as an annular diaphragm for such a coaxial speaker.

This figure is a top view of a portion of the surface material cut away to show the shape of the core material 1', in which hexagonal cells are lined up.

The shape of the node of the first resonance mode of this diaphragm was not circular but elliptical because the rigidity was directional.

For this reason, it has been difficult to perform knot driving as shown in FIGS. 1 and 2.

The present invention aims to eliminate these conventional drawbacks, and FIG. 4 shows the shape of the core material 9 of an annular flat plate diaphragm having a honeycomb sandwich structure.

The shape of the core material 9 is axially symmetrical about the center of the diaphragm.

Therefore, the shape of the node of the first resonance mode becomes a perfect circle.

This core material 9 is obtained by opening in the direction of the arrow a short shelf-like layer in which adhesive layer portions 9' and unbonded portions 9'' are patterned at equal intervals as shown in FIG. It is something that can be done.

The annular diaphragm thus obtained has a smaller radius of the nodal circle of the first resonance mode than a homogeneous diaphragm of the same shape, and can be driven by a voice coil with a smaller diameter.

This is because the core material 9 has a density gradient where the density is higher in the center and lighter in the periphery.

In addition, in FIG. 5, the dimension l of the non-adhesive layer portion 9'' is uniform.

Next, another example of the core material 9 is shown in FIG.

This example is characterized in that the length of the non-adhesive layer portion 9'' becomes shorter toward the center (1
1 < l 2 < l 3 < l 4 < l s).

That is, the length of the cell wall constituting the cell is made shorter toward the center.

By doing so, the cell size of the diaphragm becomes smaller at the center, a larger density gradient is obtained, and the nodal circle diameter becomes smaller.

Therefore, since the diameter of the nodal circle becomes smaller, the voice coil can be made smaller and the nodal circle drive becomes easier.

In the above example, the length of the adhesive layer portion 9' is uniform, but it may be made shorter toward the center like the non-adhesive layer portion 9''.

As described above, according to the present invention, it is possible to provide a speaker diaphragm that facilitates nodal drive.

[Brief explanation of the drawing]

Figures 1 and 2 are respectively cross-sectional front views of coaxial flat plate speakers using flat diaphragms, Figure 3 is a plan view of a conventional flat diaphragm with part of the surface material cut away, and Figure 4. is a plan view of the core material of the diaphragm according to the present invention, and FIGS. 5 and 6 are perspective views of each side of the concentric material before expansion. 1...Flat plate diaphragm, 2...Treble speaker, 3...Voice coil, 9...Heart material, 9'...Adhesion Layer part, 9″... Non-adhesive layer part.

Claims (1)

[Scope of utility model registration request] A plurality of speakers are arranged coaxially, and the speaker that reproduces the lower frequency has the shape of an annular flat plate, and the nodal circle of the first resonance mode of the diaphragm of the speaker is driven by a voice coil. A diaphragm for use in a coaxial flat plate speaker, wherein the diaphragm has a honeycomb sandwich structure, the cell shape of the honeycomb core material is symmetrical about the center of the diaphragm, and the cell dimensions of the honeycomb core material are symmetrical in the radial direction. A coaxial flat speaker diaphragm with a smaller center part.