JPS591034B2 - flat diaphragm - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a planar diaphragm for an acoustic transducer such as a speaker or microphone.

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 attached to the bobbin 4.

However, when an audio signal current is passed through the voice coil 5 to apply a driving force to the diaphragm, heat is generated in the voice coil 5, and the heat is transmitted through the bobbin 4 and reaches the diaphragm. The air inside the capsule a surrounded by the core material 1 and the skin materials 2 and 3 of the diaphragm expands, causing the skin materials 2 and 3 to break, and the skin materials 2 and 3 to be sensitive to heat like vinyl chloride. In the case of substances, they undergo thermal deformation.

Therefore, conventional honeycomb diaphragms are not suitable for high output applications.

The present invention attempts to solve the above-mentioned problems by allowing the air in the capsules of the honeycomb diaphragm to move to other capsules.

Hereinafter, explanation will be given with reference to the drawings. In Fig. 4, a hole 1a is made in the core material 1 near the part covered by the bobbin 4, and the capsules a in that part are communicated with each other, so that air can be aired between them. In addition, holes 3a are provided inside and outside the bobbin 4 attachment part in the skin material 3 on the back side.
is formed so that the air in the capsule a can communicate with the outside air inside and outside the bobbin attachment part.

By forming such holes 1a and 3a, the air within the capsule a near the bobbin mounting portion can freely move and communicate with the outside air, thereby preventing a particular capsule from thermally expanding.

In addition, as described above, the holes 3a formed in the skin material 3 on the back side are located on the inside and outside of the bobbin attachment part, so when the diaphragm vibrates, air inside and outside the bobbin flows through the holes 3a, la.
When the voice coil 5, which is fixed to the diaphragm via the bobbin 4, vibrates within the gap of a magnetic circuit (not shown), the resistance is reduced, allowing more efficient reproduction.

In addition, in the above embodiment, the hole 1a of the core 1 was formed only near the attachment part of the bobbin 4, but the hole 1a of the core 1 was formed only in the vicinity of the attachment part of the bobbin 4. However, if the hole 1a of the core 1 were formed in all the capsules, the temperature difference would further increase, and convection would become active. , the cooling effect becomes significant.

As described above, according to the present invention, air convection occurs between the capsules, and the air inside the capsule also communicates with the outside air through the holes formed inside and outside the bobbin handle of the skin material on the back surface. As a result, the skin material is not damaged or deformed due to thermal expansion, and it is now possible to significantly improve input resistance and achieve high output, and it also vibrates together with the diaphragm. The voice coil moves smoothly within the gap in the magnetic circuit due to the above-mentioned ventilation inside and outside the bobbin, allowing more efficient reproduction.

[Brief explanation of drawings]

FIG. 1 is an exploded perspective view of a honeycomb diaphragm, FIG. 2 is an overall perspective view, FIG. 3 is a sectional view, and FIG. 4 is a partial sectional view of a diaphragm according to an embodiment of the present invention. 1...Core material, 2,3...Skin material,
a... Capsule, 1a, 3a... Hole.

Claims (1)

[Claims] 1 In a flat diaphragm formed by using a honeycomb structure as a core material and pasting skin materials on both the front and back surfaces, holes are formed in the core material at least near the bobbin attachment part to allow air convection between the internal capsules. as well as
A flat diaphragm characterized in that holes are formed inside and outside of the bobbin attachment part of the skin material on the back side to which the bobbin is attached, so that the air in the capsule can communicate with the outside air.