JPS6090500A - Edge for speaker - Google Patents

Abstract

PURPOSE:To prevent a speaker from its failure due to thermal deformation by using an edge which is molded from polyether imide resin with superior heat resistance or a mixture whose main body is polyether imide resin. CONSTITUTION:For example, polyether imide resin whose thickness is 70mum is arranged between upper and lower metal molds at room temperature, it is heated at 240-250 deg.C by a far infrared rays heater, and the heater is removed. Immediately after that, the upper and lower metal molds are fitted, and the film is molded in the edge shape by 5kg/cm<2> pressing pressure. The edge made of polyether imide resin, which is molded in this way, has remarkably high thermal deformation temperature, and it is suitable for the edge of a on-vehicle speaker which is used under high temperature. Since its internal loss is large, an absorbing action of oscillating energy which is propagated from an oscillation board is satisfactory, and harmful resonance such as anti-resonance is also suppressed.

Description

[Detailed description of the invention] The physical properties of the speaker edge are as follows: (1) Internal loss must be moderate.

(2) It must be lightweight in order to suppress an increase in the weight of the vibration system (11'L).

(3) There are fewer ways to stretch and contract.

(4) No breathability 3゜ (5) Initial special 1 piece 1. There is little change over time.

(6) The center support capacity of the following plate is large.

One example is the shield, but since the J1 Kokamikawa Nubika Edge is used under harsh conditions (I'i'+II extremely high humidity), in addition to the above physical properties, (7) it has good heat resistance.

(8) There should be no change in physical properties within the humidity range under use.

(9) Good water resistance and moisture resistance.

is required.

Considering the conventional edge for speakers from the point of view mentioned above, it is found that edges made of woven fabric made of cotton, silk, or polyester and impregnated or coated with pheno-V resin or acrylic resin have internal loss, lightweight,
Center support, heat resistance, and temperature change are relatively good, but cutting tool properties, air permeability, changes over time, and water resistance and humidity are not sufficient.

Therefore, in recent years, especially in small-amplitude high-pitched speakers, edges made of polyester film formed by vacuum or air pressure have been put into practical use as satisfying the above-mentioned requirements except for heat resistance and temperature change characteristics.

However, the thermal f-type temperature of the polyester film is about 70°C, and at 80°C to 90°C, thermal deformation occurs and the diaphragm supporting function deteriorates.

Furthermore, when the temperature exceeds around 70° C., the Young's modulus decreases rapidly, causing a change in the diaphragm support function, which affects sound quality.

Particularly when polyester film edge is used for car speakers, for example, in the rear parcel tray, direct sunlight
Under -1 light? ii: Even when the temperature reaches 90 to 100 degrees Celsius, there are disadvantages such as heat deformation of the edges, making the speaker unusable, and changes in sound quality.
Shit/ko.

Therefore, this invention has an excellent heat resistance of 1 m lll'? or a mixture mainly composed of polynythelimide resin, which solves the drawbacks of the above-mentioned conventional examples.Examples will be described in more detail below.

[Example 1] A polyetherimide resin film with a thickness of 70 ttm was placed between the lower molds at room temperature, heated to 240°C to 250°C with a far infrared heater, the heat was removed, and the film was immediately heated. The upper and lower molds were combined and molded into an edge shape with a press pressure of 5~.[Example 2] Polynythelimide resin was mixed with 3ω1/% alumina powder, and then molded into a 70 μm thick film.

The film was placed between the upper and lower molds at room temperature and heated to 240°C to 250°C with a far-infrared heater, then the heater was removed, and the upper and lower molds were immediately put together and formed into an edge shape with a press pressure of 5 (-). A part of the molded edges in Examples 1 and 2 was cut out as a test piece to measure the density, internal loss,
The heat distortion temperature items were measured.

(However, the heat distortion temperature is A S T IV4: D 64
8) As shown in the above table, the edge according to the present invention has the advantages of extremely high thermal deformation temperature and high internal loss.

Therefore, 1) it is most suitable for use in car speakers used under high temperatures due to 11 advantages, and A! link rate? ! When we measured the change in PI, we found that while the Young's modulus of polyether resin decreased by 50% from 70°C to 100°C,
In the edge of this invention, the Young's modulus decreases by 27% from room temperature to 170°C, and the change in Young's modulus from room temperature to 100°C, which is considered the highest temperature in a car, is 17%.
It was found that the change in the physical properties of the edge with respect to temperature was improved.

In addition, since the internal loss of the 7Jl is large, the vibration energy propagated from the diaphragm was well absorbed by I1, and it was also effective in suppressing harmful resonances such as anti-resonance.

As explained in Section 2 below, the present invention is an edge formed by molding a polyetherimide resin or a mixture mainly composed of a polyetherimide resin, and has heat resistance and physical properties due to temperature changes. °j changes can be improved,
In particular, it has an excellent effect as an edge for car speakers, and even when used under high temperatures inside a car, it was able to suppress the occurrence of speaker malfunctions and changes in sound quality due to temperature changes.

Furthermore, since the internal loss is relatively large, it has good vibration energy absorption properties and has the effect of suppressing harmful co-alignment, etc.
As a result, we were able to provide a speaker with a more even frequency response.

Claims (1)

[Claims] Processed with polyetherimide or polyetherimide,
An edge for a speaker characterized by being made of a mixture of sinter and sinter. 1