JPS59191997A - Speaker diaphragm - Google Patents

Abstract

PURPOSE:To prevent the cavity resonance of a defective cell and to reduce the third harmonic distortion by folding the fringe part of a surface material to cover the opening surface of the defective cell at the outer circumferential part of a honeycomb core material. CONSTITUTION:The surface materials 3 and 3' are folded along the utmost outer circuimference part of a diaphragm, and the fringe parts 15 and 16 of these materials 3 and 3' are adhered to each other at their junction sides to cover the opening surface of the defective cell at the utmost outer circumference of the diaphragm. In this case, the diameters of materials 3 and 3' are set larger than the diameter of a honeycomb core material 2. Then the material 2 is adhered to the part 15 of the material 3 extruding outside over the material 2 to cover the opening surface of the defective cell.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a speaker diaphragm having a sandwich structure in which surface materials are bonded to both surfaces of a nicum core material.

Construction of a conventional example and its problems 1 First, a conventional speaker diaphragm of this type will be explained.

FIG. 1 shows a block of honeycomb material. This honeycomb material block 1 is made by laminating many sheets of metal foil, etc., and
As shown in FIG. 2, adjacent metal foils are bonded at regular intervals. A part of the honeycomb material block 1 shown in FIG. 1 is cut along a-a', and as shown in FIG. 3, b'
When the material is rotated and expanded in the force direction, a honeycomb core material 2 having hexagonal cells as shown in FIG. 4 is obtained. As shown in FIG. 5, surface materials 3.3
′ by gluing the sandwich structure diaphragm 4.
is configured. 5 is a voice coil bonded to the lower surface of the diaphragm 4 by adhesive.

FIG. 6 shows a speaker using the diaphragm 4 described above.

In FIG. 6, 6 is a magnetic circuit, and this magnetic circuit 6
is composed of an annular magnet 9 on a plate 8 with a center ball 7 integrally formed in the center, and an annular upper plate 1o fixed to the upper surface of this magnet 9, and the inner peripheral surface of this upper plate 10 and An annular magnetic gap 11 is formed between the outer peripheral surfaces of the center ball 9. Reference numeral 12 denotes a frame coupled to the magnetic circuit 6, and the diaphragm 4 is incorporated into this frame 12. 1
Reference numeral 3 designates an annular edge member, and the inner circumferential portion of this edge member 13 is bonded to the diaphragm 4, and the outer circumferential portion is bonded to the circumferential edge of the frame 12.

14 is a damper that supports the middle part of the voice coil 5, and the lower part of this voice coil 5 is connected to the magnetic gap 11.
is inserted into.

”2. The diaphragm 4 of the conventional speaker has the fourth diaphragm 4 as described above.
Surface materials 3, 3' are applied to the upper and lower surfaces of the honeycomb core material 2 shown in the figure.
The diaphragm 4 has a structure in which the diaphragm 4 is glued together, and incomplete cells are formed at the outermost periphery of the diaphragm 4.

Cell X and incomplete cell Y at the outermost periphery in Figure 4
Cell

Speech is generated using a diaphragm with a structure similar to the above conventional structure,
This has the drawback of significantly deteriorating the sound quality of the speaker and causing distortion. This is because the plate resonance frequency of the surface material of the incomplete cell Y is reduced to 1/3 to 1/4 compared to the plate resonance frequency of the surface material of the perfect cell This is because the third-order distortion increases.

OBJECTS OF THE INVENTION The present invention eliminates the above-mentioned conventional drawbacks and provides a speaker diaphragm with low third-order distortion and high characteristics.

Structure of the Invention In order to achieve the above-mentioned object, the present invention makes the diameter of the surface material larger than the diameter of the honeycomb core material, and extends the peripheral edge of the surface material that protrudes outward from the honeycomb core material along the outer peripheral surface of the honeycomb core material. The peripheral edges are adhesively bonded to each other, and the openings of the incomplete cells on the outer periphery of the above-mentioned nicum core are closed.

By closing the opening surfaces of the incomplete cells, the third-order strain is reduced, resulting in high characteristics.

DESCRIPTION OF EMBODIMENTS A speaker diaphragm according to an embodiment of the present invention will be described below with reference to the drawings.

In Fig. 7, reference numerals 15 and 16 are the peripheral edges of the surface materials 3 and 3' that are bent along the outermost circumferential surface of the diaphragm 4, and these peripheral edges 16 and 16 are bonded together at the joint surface to form the outermost circumference. The opening surface of the incomplete cell is closed.

This is done by forming the diameter of the surface materials 3, 3' larger than the diameter of the honeycomb core 2, and bending the peripheral edge portions 13, 16 of the surface materials 3, 3' that protrude outward from the honeycomb core 2. The opening surface of the incomplete cell is closed.

In the case shown in FIG. 8, the lower surface material 3' is thick enough to protrude outward by the height of the honeycomb core material 2, and this peripheral edge 16 is... Bend it out of the way...
- The opening surface of the incomplete cell is closed by adhering to the peripheral edge 15 of the upper surface material 3 that protrudes outward from the Nikum core material 2.

Effects of the Invention The speaker diaphragm of the present invention is constructed as described above, and by closing the opening surfaces of the incomplete cells by bending the peripheral edge of the surface material, the cavity resonance of the incomplete cells is prevented and the Third harmonic distortion is reduced.

By using the periphery of the surface material, the appearance quality is excellent, the strength is superior compared to those using a separate material, and the increase in mass is small, which improves efficiency. There will be no possibility of a decrease.

[Brief explanation of the drawing]

Fig. 1 is a perspective view of a Nicomb wood block, Fig. 2 is an enlarged sectional view of the same main part, Fig. 3 is a perspective view of a cut Nicomb wood block, and Fig. 4 is a top view of a portion of the honeycomb core material. Figure, 5th
The figure is a side sectional view of a voice coil attached to a conventional speaker diaphragm, FIG. 6 is a sectional view of a speaker using a conventional diaphragm, and FIGS. 7 and 8 are for the speaker of the present invention. FIG. 3 is a cross-sectional view showing an example of a diaphragm. 2- Honeycomb core material, 3, 3'...Surface material, 4
・・Diaphragm, 15.16 ・・Periphery. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure φ α Figure 2 Figure 4 Figure 5 Figure 3 2 Figure 6 Figure 7 Figure 8

Claims (1)

[Claims] The diameter of the surface material to be bonded to both sides of the honeycomb core material is made larger than the diameter of the honeycomb core material, and the peripheral edge of the surface material that protrudes outward from the honeycomb core material is aligned with the outer periphery of the honeycomb core material. Bend it and glue the edges together,
A speaker diaphragm made by closing the openings of the incomplete cells on the outer periphery of the above-mentioned No.