JPH0477095A - Diaphragm for speaker - Google Patents

Abstract

PURPOSE:To enhance the elastic modulus and to improve the fragile property by using a thermoplastic liquid crystal polymer as major component and forming a meandering groove on the surface of a metallic die. CONSTITUTION:When a thermoplastic liquid crystal polymer 5 is heated, it is molten and the viscosity is decreased and an excellent fluidity is represented and when the polymer is injected in a metallic die of speaker diaphragm shape by injecting molding, the polymer 5 is cooled and solidified while being orientated on the inner surface of the metallic die. In this case, since the direction of the fluidity of the liquid crystal polymer 5 is meandered on the inner surface of the metallic die by forming a meandering groove 3 locally on the inner surface of the metallic die, the orientation of the liquid crystal polymer 5 is meandered. Thus, the elastic modulus for the speaker vibration is enhanced and the fragile property of the diaphragm for the speaker is improved.

Description

[Detailed Description of the Invention] Industrial Application Field The present invention is applicable to various sounds #JIri! This invention relates to a speaker diaphragm used in a U-type device.

Conventional technology Speaker diaphragms have traditionally been made of paper bulbs, and their performance is characterized by the specific elastic modulus E/ρ of the diaphragm.
(E1 elastic modulus, ρ, density) is required to be as large as possible, and it is required to have an appropriate internal loss in order to smooth the frequency characteristics in the high frequency range.

Conventionally, in order to increase E/ρ, a method has been used in which a reinforcing material such as mica powder or carbon fiber is mixed into a diaphragm mainly made of paper valves. Furthermore, in recent years, diaphragms made of synthetic resin mixed with reinforcing materials have been used to improve E/ρ. Regarding internal loss, paper pulp has a moderate internal loss, and in order to increase the internal loss of synthetic resin diaphragms, the surface has been coated with a flexible material.

A conventional speaker diaphragm will be explained below.

FIG. 4 shows a flow section of a resin obtained by conventional injection molding of synthetic resin, where 6 is an injection section and 7 is a molding section.

FIG. 4 shows a speaker diaphragm 8 obtained by conventional injection molding of synthetic resin.

FIG. 5 shows a conventional speaker diaphragm 9 mainly composed of paper bulbs.

The speaker diaphragm configured as above will be explained. First, the speaker diaphragm 8 obtained by injection molding of synthetic resin is manufactured by cooling and solidifying the synthetic resin polymer and fibrous filler while being oriented in the flow direction of the resin, especially when reinforcing material such as carbon fiber is mixed. do.

Furthermore, a method has been used in which carbon fiber is mixed as a reinforcing material into the speaker diaphragm 9, which is mainly made of paper pulp.

Problems to be Solved by the Invention However, in the above-mentioned conventional configuration, the speaker diaphragm 8 obtained by injection molding of synthetic resin is oriented in the flow direction of the resin, so that the speaker diaphragm 8 with a smooth surface has a smooth surface. Although the plate 8 has very good strength in the resin orientation direction, the strength is weak in the direction perpendicular to the resin orientation direction, and the speaker diaphragm is likely to crack when the speaker is driven. Further, in the method of mixing carbon fiber into paper pulp, there is a limit to the amount of carbon fiber mixed in, and there is a limit to the increase in E/ρ, which is not satisfactory.

The present invention solves the above conventional problems, and aims to provide a speaker diaphragm having a high E/ρ, moderate internal loss, and improved brittleness.

Means for Solving the Problem In order to solve this problem, the speaker diaphragm of the present invention is made of a thermoplastic liquid crystal polymer as a main component, and is molded with a molded metal so that at least one of the surfaces of the diaphragm has a meandering shape. It can be obtained by injection molding by creating meandering grooves on the surface of the mold.

Function In this configuration, the liquid crystal polymer or the liquid crystal polymer and the fibrous filler are cooled and solidified while being oriented in the flow direction of the resin. The flow direction of the resin is such that the resin surface of the speaker diaphragm has a meandering shape, and the meandering orientation of the resin increases the vibration elasticity of the speaker, improves the fragility of the speaker diaphragm, and reduces moderate internal loss. Become what you have.

EXAMPLE Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 1 shows a flowing part of a resin mainly composed of a thermoplastic liquid crystal polymer in a first embodiment of the present invention.
2 is an injection part, 2 is a molding part, and 3 is a meandering groove part.

FIG. 2 shows a speaker diaphragm 4 obtained from the present invention.

The speaker diaphragm configured as above will be explained.

When heat is applied to a thermoplastic liquid crystal polymer, it melts, its viscosity decreases, and it exhibits excellent fluidity. When it is filled into a mold in the shape of a speaker diaphragm by injection molding, the polymer is oriented on the surface of the mold. Cool and solidify. At this time, by partially forming meandering grooves on the mold surface, the fluidity direction of the liquid crystal polymer meanders on the mold surface.
The orientation of the liquid crystal polymer is also meandering. This makes it possible to improve the fragility of the speaker diaphragm. That is,
The liquid crystal polymer has a high modulus of elasticity in the direction in which the resin is oriented, but has a low modulus in the direction perpendicular to the direction in which the resin is oriented, so that portions with a low modulus of elasticity cause cracks in the speaker diaphragm. By having the meandering groove 3, the fragility of the speaker diaphragm can be improved.

The extended molecular chain structures of a speaker diaphragm obtained by the present invention and a speaker diaphragm obtained by a conventional method are shown below.

FIG. 3 shows the molecular state of the speaker diaphragm of the present invention in the molecular state of the liquid crystal polymer 5, showing the state of the liquid crystal polymer 5 in melting, injection molding, and solidification. A serpentine groove 3 is formed on the mold surface, and the speaker diaphragm obtained by the present invention is free of brittleness, compared to the speaker diaphragm obtained by the conventional structure mold shown in FIG. Since the elongated molecular chain structure is uniform in one direction, the speaker diaphragm is prone to cracks in the flow direction of the resin.

Effects of the Invention As explained above, the present invention provides a speaker diaphragm mainly composed of a thermoplastic liquid crystal polymer, by adopting a structure with a meandering orientation state on the diaphragm surface.
A speaker diaphragm with excellent high elastic modulus and no brittleness can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing a resin flowing part of a mold when molding and manufacturing a speaker diaphragm according to an embodiment of the present invention, FIG. 2 is a half-sectional front view of the same diaphragm, and FIG. The figures are explanatory diagrams showing the manufacturing process of the present invention, FIG. 4 is a perspective view showing the resin flow part of the mold when molding and manufacturing a conventional speaker diaphragm, and FIGS. 5 and 6. 7 is a half-sectional front view of a conventional speaker diaphragm, and FIG. 7 is an explanatory diagram showing the manufacturing process of the conventional speaker diaphragm. 1... Injection part, 2... Molding part, 3...
...Meandering groove, 4...Resin diaphragm, 5
・・・・・・Name of liquid crystal polymer agent Patent attorney Shigetaka Awano and 1 other person 2nd figure Melt↑? The opening of the store was also done with Hiroaki Gekihi. IPJ-Minute 3 Contains Station Tortoise 1 Seventh Seki Lλ51-5 Main Entry Section C-Force Maneuvering Force I Reaction Busy Song Theory Appearance Qiwa Ue wo Foss

Claims (1)

[Claims] A speaker diaphragm whose main component is a thermoplastic liquid crystal polymer and which has meandering grooves formed on at least one of its surfaces.