JPS6236397Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a dust cap for a speaker.

Generally, the purpose of a speaker's dust cap is to prevent dust from getting into the magnetic circuit, but as the diaphragm vibrates, the dust cap itself radiates sound, which is combined with the sound radiated by the diaphragm and becomes a major factor in determining the frequency characteristics and other characteristics of the speaker.

If this dust cap has a large diameter,
Those with a structure made by press-forming light metal foil such as aluminum, or those with a structure made by press-forming after papermaking pulp fibers are used, but these structures have relatively high rigidity and low internal loss, so , causing high-Q resonance especially in the high range, increasing distortion and significantly deteriorating sound quality.
This caused peaks and dips in the frequency response.

The present invention improves on these conventional drawbacks and is characterized by a base layer consisting of a three-dimensional intertwining of a fiber layer with a non-woven structure and a polymeric elastomer with a continuous microporous structure. It has a structure in which a sheet having almost the same structure as that of natural leather and a base fabric are overlaid and integrally molded under heat and pressure.

Hereinafter, one embodiment of the present invention will be described along with its manufacturing process with reference to FIGS. 1 to 3.

() A cotton cloth 1 with a thickness of 0.3 mm is prepared as a base cloth constituting the dust cap, and this cotton cloth 1 is immersed in a phenolic resin solution having a weight concentration of 45%, and then air-dried.

() Thereafter, this cotton cloth is heated and pressed under the conditions of a mold temperature of 210°C, a pressing time of 30 seconds, and a pressing pressure of 2 kg/cm ² to form it into a dome shape.

() A dome-shaped molded article (cotton cloth 1) is immersed in a 35% weight concentration phenol resin solution, and then air-dried.

() Thereafter, a sheet 2 having a base layer having a random three-dimensional structure in which this cotton cloth 1 is three-dimensionally intertwined with a fiber layer having a non-woven structure and a polymer elastomer having a continuous microporous structure is formed. are overlapped and heated and pressurized to penetrate the surface portion of the sheet 2 that contacts the cotton fabric 1 between the weaves of the cotton fabric 1 and thermally fuse them, thereby bonding the cotton fabric 1 and the sheet 2, and at the same time forming a predetermined dome. Shape into shape.

In this example, the seat 2 is made of synthetic leather Clarino (registered trademark) USF- manufactured by Kuraray Co., Ltd.
BL-04 (black) was used.

As shown in Figure 2, Clarino synthetic leather is a random synthetic leather made by infiltrating polyurethane resin solution between polyimide fiber layers of a non-woven fabric structure, and three-dimensionally intertwining this fiber layer with a polyurethane elastomer having a continuous microporous structure. On the surface of the base layer (non-woven fabric layer) 3 having a three-dimensional three-dimensional structure, a surface layer (grain layer) 4 made of a polyurethane elastomer having a continuous porous structure even finer than the above-mentioned polyurethane elastomer is continuously connected to the base layer 3. It has a structure that is almost the same as that of natural leather.

Specifically, as the sheet 2, a sheet with basic physical properties of 0.80 mm in thickness, 240 g/ ^m2 in weight, and 0.3 in specific gravity (apparent density) was used.
The above cotton cloth 1 was superimposed on the back side of the base layer 3 with a rough texture, and the mold temperature was 130°C and the pressing time was
Heat and press them together for 30 seconds at a press pressure of 2 kg/cm ² to form them into a dome shape. The thickness of sheet 2 after molding was 0.4 mm.

The reason why the cotton cloth 1 is superimposed on the back surface of the sheet 2 is to make the adhesion between the coarse base layer 3 and the cotton cloth 1 stronger and more complete.

In addition, in the step () above, soaking the molded product (cotton cloth 1 again with the phenolic resin solution)
In the process of overlapping the sheet 2 and the molded product and applying heat and pressure to bond and mold, the gas generated when the phenol resin reacts and hardens soaks the adhesive surface of the sheet 2 to improve adhesiveness. It is.

In the dust cap manufactured as described above, the sheet 2 having a continuous microporous structure is molded during the molding process to the extent that it retains its original physical properties, and maintains flexible elasticity and moderate vibration loss. The soft elasticity and moderate vibration loss of this seed 2 and the rigidity of the cotton fabric 1 imparted by the excipient are combined, and a dust cap with moderate rigidity, flexible elasticity, and vibration loss is imparted. Therefore, high-Q resonance, especially in the high range, is suppressed and distortion is also reduced, so there is no deterioration in sound quality due to dust cap, and peaks and dips in frequency characteristics can also be suppressed. In addition, by utilizing the heat fusion properties of the sheet 2, the surface portion of the basic layer 3 of the sheet 2 is infiltrated between the weaves of the cotton fabric 1 during heating and pressure forming.
and sheet 2, there is no need for a bonding process, which not only greatly simplifies the manufacturing process, but also makes the quality uniform and facilitates mass production. Since there is no adhesive involved, there is no appearance defect. Furthermore, Sheet 2 has excellent durability such as surface strength, abrasion resistance, bending resistance, bending fatigue resistance, etc., and is also excellent in the surrounding environment, especially in terms of cold and heat resistance (-20℃ to 70℃). It has the advantage of being able to maintain its initial acoustic characteristics for a long time and being excellent in terms of quality stability.

In addition, in the above example, the sheet 2 and the cotton cloth 1 were bonded together using the thermal adhesive properties of the sheet 2.
A sheet of hot-melt adhesive may be interposed between the sheet 2 and the cotton cloth 1, and the adhesive may be bonded by heating and pressing. In this case, the above step () is not necessary, and the manufacturing process is further simplified.

As described above, the present invention provides a sheet 2 having a base fabric such as a cotton cloth 1, a base layer 3 in which a fiber layer having a non-woven fabric structure and a polymer elastomer having a continuous microporous structure are intertwined three-dimensionally. Because it has a structure in which the parts are stacked together and molded under heat and pressure, it has appropriate rigidity, flexible elasticity, and vibration loss, and has excellent advantages such as uniform quality and ease of mass production.

[Brief explanation of the drawing]

1 to 3 are diagrams showing the structure of the present invention. 3 is a base layer, 2 is a sheet, and 1 is a base fabric.

Claims (1)

[Scope of utility model registration request] On the surface of the base layer 3, which is a three-dimensional intertwining of a synthetic fiber layer with a nonwoven structure and a polymer elastomer having a continuous microporous structure, a continuous porous structure that is even finer than the polymer elastomer is continuous to the base layer 5. A dust cap for a speaker is formed by superimposing a sheet 2 on which a surface layer 4 made of a polymer elastomer having a surface layer 4 is formed and a base fabric 1 and integrally molding them under heat and pressure.