JPH0667030B2 - Vibration plate for speakers - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a diaphragm for a speaker, which is made of a molded product obtained by impregnating lacquer into a chitin-mixed material used for an acoustic output device or the like.

2. Description of the Related Art In recent years, cassette tape recorders, microcassette tape recorders, and in the hi-fi stereo industry, speakers with excellent output sound pressure, distortion rate, and flatness have been desired even in the acoustic characteristics of speakers as acoustic output devices. The diaphragm for speakers, which influences the acoustic characteristics, is becoming more and more important.

A speaker is generally a vibration system such as a diaphragm, a voice coil bobbin, a voice coil, a magnet, a pole, a plate,
It consists of a magnetic circuit system consisting of a yoke. When a voice current flows through a voice coil in a uniform magnetic field, a vertical electromagnetic force is generated in the voice coil and vibrates according to the current.
This vibration is correctly transmitted to the vibration of the diaphragm and emitted as a sound wave (for example, Toshio Hayasaka: Introduction to Acoustic Engineering, Nikkan Kogyo Shimbun).

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention However, it is ideal that the diaphragm of the speaker makes a piston motion over the frequency band used, and if the diaphragm is deformed or divided vibration occurs during vibration, sound pressure-frequency characteristics and distortion are generated. The rate, phase characteristics, etc. are deteriorated, which hinders high fidelity reproduction. Also, conventional paper cone diaphragms and plastic diaphragms have E / ρ (where E: elastic modulus,
Since ρ: density) is small, there is a drawback that the high frequency resonance frequency is low and the speaker cannot reproduce up to the high frequency range.

In view of the above problems, the present invention provides a speaker diaphragm having a high high resonance frequency, which does not cause the diaphragm to deform or generate divided vibration during vibration.

Means for Solving the Problems In order to achieve this object, the speaker diaphragm of the present invention is configured by using a molded product obtained by impregnating lacquer into a material in which kraft pulp and chitin which is a natural polymer are mixed. Has become.

Action The present invention, because the sheet-shaped material is composed of a material in which chitin, which is a natural polymer material having a large elastic modulus, and kraft pulp having a large mechanical internal loss are mixed, the effect of chitin is obtained. The flexural rigidity of the diaphragm is extremely high, the diaphragm does not deform during vibration and split vibration does not occur, the mechanical internal loss is large due to the effect of kraft pulp, and the effective internal loss due to the effect of lacquer. Is large and has excellent water resistance. Therefore, a speaker having excellent sound pressure-frequency characteristics, distortion rate, phase characteristics, and reliability can be obtained. Further, since this diaphragm material uses a material containing kraft pulp as a main component, it can be manufactured by a conventional papermaking method, and since it is treated with lacquer by impregnation, it is very excellent in mass productivity.

Example Hereinafter, a speaker diaphragm according to an example of the present invention will be described.

The speaker diaphragm in one embodiment of the present invention is formed by impregnating lacquer into a material obtained by mixing kraft pulp and chitin, which is a natural polymer.

Hereinafter, the method for manufacturing the diaphragm of the present embodiment will be described. First, the weight ratio of kraft pulp and natural polymer chitin (powdered, 120 mesh pass) is 7:
The mixture is mixed at a ratio of 3 and is formed into a paper by a round net method, and this is impregnated with a lacquer solution diluted with an organic solvent (solid content 8 wt%). A dome-shaped diaphragm with a diameter of 28 mm and a basis weight of 30 g / m ² is used.

As described above, the speaker using the diaphragm in which the kraft pulp and the chitin that is a natural polymer are mixed and further impregnated with lacquer, the diaphragm is not deformed, the split resonance does not occur, the distortion rate is small, and the high frequency range is high. The resonance frequency is high, good acoustic characteristics are obtained, the strength in wet is about twice as high as that of the conventional paper cone, and the water resistance is high and the reliability is excellent.

Needless to say, similar effects can be obtained regardless of the shape of the diaphragm, such as a flat diaphragm or a cone diaphragm, as well as the dome diaphragm.

Effects of the Invention As described above, the present invention is composed of a material obtained by mixing papers of chitin, which is a natural polymer material having a large elastic modulus, and kraft pulp having a large mechanical internal loss,
Due to the effect of chitin, the flexural rigidity of the diaphragm is very large, the diaphragm is not deformed or divided during vibration, and the mechanical internal loss is large due to the effect of kraft pulp. Internal loss is large,
It also has excellent water resistance. Therefore, a speaker having excellent sound pressure-frequency characteristics, distortion rate, phase characteristics, and reliability can be obtained. Further, since this diaphragm material uses a material containing kraft pulp as a main component, it can be manufactured by a conventional papermaking method, and since it is treated with lacquer by impregnation, it is very excellent in mass productivity.

Claims (1)

[Claims] 1. A diaphragm for a speaker, comprising a molded product obtained by impregnating lacquer into a material obtained by mixing kraft pulp and a chitin which is a natural polymer.