JPS5925558B2 - flat diaphragm - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a planar diaphragm used in acoustic transducers such as speakers and microphones.

Among planar diaphragms, a honeycomb diaphragm is formed by using a honeycomb structure made of aluminum foil or other material as a core material 1, and pasting skin materials 2 and 3 such as metal sheets or synthetic resin sheets on both the front and back sides of the core material 1. is the skin material 3 on the back side.
A bobbin 4 is fixed to the side, and a voice coil 5 is wound around the bobbin 4.

However, when an audio signal current is passed through the voice coil 5 to provide a driving force to the diaphragm, heat is generated in the voice coil 5, and when that heat is transmitted through the bobbin 4 and reaches the diaphragm, the The air inside the capsule a surrounded by the core material 1 and the skin material 2.3 near the bobbin-4 of the diaphragm expands, causing the skin materials 2 and 3 to break, or the skin materials 2 and 3 to be made of vinyl chloride. If the material is sensitive to heat, it will undergo thermal deformation.

Therefore, in such a case, it is necessary to prevent heat from accumulating inside the capsule a, and for this purpose, the skin material 2,
Although it is sufficient to form a ventilation hole in the hole 3, there is a possibility that the output sound pressure characteristics will be adversely affected.

However, if the capsules a are communicated with each other, heat convection will occur and heat will no longer be trapped in a particular capsule.

In view of the above points, an object of the present invention is to provide a planar diaphragm in which a core material is provided with ventilation holes so that capsules communicate with each other.

Hereinafter, the present invention will be described in detail with reference to FIG. 4 and subsequent figures.

First, when the sheet material (reinforced plastic sheet containing carbon fiber, carbon graphite, glass fiber, etc., aluminum foil, etc.) 6 to be the core material is fed out from the roll as shown in FIG. A plurality of pores 6a are formed in the sheet material 6 by passing through a feeding section consisting of a needle roller 8.

Next, as shown in FIG. 5, the sheet material 6 having the pores 6a is cut into sheets 6, to 6n at predetermined lengths, and an adhesive 9 having a width A is applied to the sheets. The sheets 61 to 6o-1 with a mutual spacing of 3A are stacked so that the adhesive 9 has a phase difference of 180 degrees.Finally, the sheets 6 and 6n are stacked one on top of the other at a 180 degree phase difference. to be joined to.

Next, the adhesive 9 is divided into a plurality of pieces in a direction perpendicular to the direction in which the adhesive 9 is applied, resulting in the state shown in FIG. 6, and then spread out in the direction of the arrow X.

As a result, a core material having the shape and structure shown in the honeycomb core material 1 in FIG. 1 is completed.

Then, a planar diaphragm is formed by pasting skin materials on both the front and back surfaces of this core material.

In the planar diaphragm produced through the above process, pores remain in the non-adhered parts of the sheets 6 to 6n that make up the core material, so the capsules surrounded by the core material and the front and back skin materials are Since the capsules are not sealed and communicate with each other through the pores of the core material, heat within the capsules is convected and no longer accumulates in a particular capsule.

FIG. 7 shows another embodiment, in which sheets 6'1 to 6'o that do not form pores are bonded and overlapped with adhesive 9' in the same manner as described above, and each sheet 6'1 to 6'o is A hole 10 is formed by passing a jig (not shown) from the direction of the arrow Y so as to penetrate the portion of the hole 10 to which the adhesive 9' is not applied.

The sheet 6 constituting the core material can also be obtained by the method shown in FIG.
Since holes are formed in the non-adhered portions '1 to 6'o, the capsules communicate with each other, so that heat convection occurs.

As described below, according to the present invention, a plurality of sheet materials are adhesively polymerized alternately at predetermined intervals, and skins are adhered to both the front and back surfaces of a honeycomb core material formed by spreading the polymerized sheet materials. In the planar diaphragm having a large number of capsules formed therein, holes are formed in the non-adhered portions of the sheet material serving as the partition walls of the capsules, which are not bonded to adjacent sheet materials, so that all of the large number of capsules are communicated with each other. It is characterized by

Therefore, the skin material can be attached to both the front and back sides of the core material with the same strength as before, and the capsules surrounded by the core material and the skin material communicate with each other through the holes, which prevents them from being affected by heat. This makes it possible to realize a flat diaphragm that does not require a flat diaphragm.

Further, since there is no fear that the holes will be blocked by pasting the skin material, even if the holes are made small, they are effective against the heat that is applied when the diaphragm is used.

Furthermore, since ventilation is provided through the holes, the strength of the core material is not significantly weakened, and there is no need to worry about damaging the characteristics of the diaphragm.

[Brief explanation of the drawing]

Fig. 1 is an exploded perspective view of a flat diaphragm, Fig. 2 is an overall perspective view, Fig. 3 is a side view, Fig. 4 is an explanatory diagram of pore formation in a sheet material, and Fig. 5 is an illustration of honeycomb core formation. FIG. 6 is a diagram showing the division of the polymerized sheet of FIG. 5, and FIG. 7 is a diagram illustrating hole formation in the divided sheet of another embodiment.

Claims (1)

[Scope of Claims] 1. A honeycomb core material formed by adhering and polymerizing a plurality of sheet materials alternately at predetermined intervals and spreading the polymerized sheet materials, and then adhering skin materials to both the front and back surfaces of the honeycomb core material. In a planar diaphragm having a large number of capsules, holes are formed in the non-adhered portions of the sheet materials that are partition walls of the capsules, which are not bonded to adjacent sheet materials, so that all of the large number of capsules are communicated with each other. Features a flat diaphragm. .