JPH0241989Y2 - - Google Patents

Description

[Detailed Description of the Invention] <Technical Field> The present invention relates to a diaphragm for a speaker, and more particularly, to an improvement of a diaphragm for a speaker, which is formed by bonding a reinforcing skin material to the front surface of a foamed resin substrate.

<Prior art> As shown in Figure 4, a conventional speaker diaphragm is constructed by pasting a reinforcing skin material b such as metal foil on the front surface of a simple flat foamed resin substrate a. . Note that c in the figure is an attachment edge member provided continuously around the skin material b.

As described above, using a foamed resin material as the substrate a has the advantage that the entire diaphragm can be manufactured lightweight and safely, but has the following drawbacks.

In other words, with foamed resin materials, about 1.5% of gas remains inside the beads at the time of molding, and in this state, if the surrounding environment reaches a high temperature of 60 to 70 degrees Celsius, the residual gas will be released outside the beads. It comes out. Therefore, in the conventional speaker diaphragm described above, residual gas flows out from the foamed resin substrate a in a high-temperature environment due to heat released from surrounding electric circuits, etc., and the outflow gas damages the substrate a and the skin material b. In the worst case, the skin material may float up, causing inconvenient situations such as noise such as chatter, distortion of sound, and poor appearance. Therefore, in order to prevent such defects from occurring as much as possible, conventionally, the foamed resin substrate a is heated approximately after molding.
It was necessary to leave it for 30 days to reduce the residual gas to about 0.9% or less before applying skin material b, which required a great deal of effort and time to manufacture.

<Purpose> The present invention was made in view of the above-mentioned conventional situation, and its purpose is to provide a substrate made of foamed resin,
Even if a speaker diaphragm is manufactured using a material that contains a lot of residual gas immediately after molding, the manufacturing process can be improved by preventing gas from accumulating between the foamed resin substrate and the skin material. It is an object of the present invention to provide a speaker diaphragm that is easy to use and can maintain excellent performance for a long period of time even when used in a high-temperature environment.

<Embodiments> First, specific embodiments of the speaker diaphragm according to the present invention will be described with reference to the drawings.

As shown in FIGS. 1 and 2, a reinforcing skin material 2 made of metal foil is bonded to the front surface (in this figure, the top surface) of a substrate 1 made of a foamed resin material having an overall disk shape. , an attachment edge member 3 is continuously provided on the outer periphery of the skin material 2,
In addition, on the front part of the foamed resin substrate 1, in order to allow gas generated from within the resin to smoothly flow out to the outside of the substrate 1 in a high-temperature environment,
A plurality of gas venting grooves 4 that are open to the sides of the substrate 1 at the peripheral edge are formed in a checkerboard pattern by molding, cutting, or other means.

In the speaker diaphragm configured as described above, even if the gas remaining inside the foamed resin substrate 1 flows out from the foamed resin substrate 1 when it is used in a high temperature environment, the outflowing gas is transferred between the substrate 1 and the skin. The skin material 2 moves smoothly within the recessed grooves 4 and flows out to the outside of the substrate 1 without intruding into the adhesive surface between the skin material 2 and the substrate 1, causing the skin material 2 to rise from the substrate 1. Such conventional drawbacks do not occur.

In the above embodiment, the degassing grooves 4 are formed in a checkerboard pattern, but the shape may be arbitrary, such as radial, continuous hexagonal, etc. Variations are possible.

Further, in the above embodiment, the degassing grooves 4 are opened to the sides of the substrate 1, but as shown in FIG. The gas may be made to flow out to the rear of the substrate 1 by continuously providing discharge holes 5 extending to the rear of the substrate 1 (downward in this figure).

<Effects> In summary, the speaker diaphragm according to the present invention is composed of a reinforcing skin material bonded to the front surface of a foamed resin substrate, in which the reinforcing skin material is metal foil, and the foamed resin substrate is made of metal foil. It is characterized in that the front surface of the substrate is formed with grid-like or radial gas venting grooves 4 that are open to the sides of the substrate.

The effects achieved by the above characteristic configuration are as follows.

That is, as detailed in the explanation of the previous embodiment, even if the surroundings become a high-temperature atmosphere and residual gas flows out from inside the foamed resin substrate, the outflow gas will
This allows the gas to flow smoothly to the outside of the board through the recessed groove for venting formed on the front surface of the board, without penetrating the adhesive surface between the board and the skin material. Inconvenient situations such as lifting of the skin material due to gas accumulation do not occur, which is the case with previous models, and the durability can be maintained over a long period of time. This makes it possible to maintain the same performance as before.

Furthermore, as mentioned above, the residual gas flowing out from inside the foamed resin substrate can now be effectively flowed out of the substrate, so as the foamed resin substrate,
There is no problem even if a material containing a large amount of residual gas immediately after molding is used, and therefore, it has become possible to manufacture a speaker diaphragm easily and in a short time.

In addition, with conventional speaker diaphragms of this type,
The reinforcing skin material is made of plastic sheet,
There is a plastic sheet with holes for degassing (for example, Japanese Patent Publication No. 15869/1986).
When gas venting holes are formed in the reinforcing skin material in this way, the skin material tends to tear at the gas venting holes, resulting in a decrease in strength. On this point, in the present invention, the reinforcing skin material, which is easy to tear, does not have a gas vent hole, but the foamed resin substrate, which is hard to tear, has a gas vent hole, and the two are bonded together. No decrease in strength occurs.

Additionally, if a relatively thick foamed resin substrate is completely attached to a reinforcing skin material without venting holes, it becomes difficult to bend and the resistance to vibration increases, resulting in poor acoustic properties. In our design, there is a recessed groove along the joint surface between the reinforcing skin material and the foamed resin substrate, and the joint is divided into many small parts, which makes the whole part easier to bend and has less resistance to vibration. As a result, excellent acoustic characteristics can be obtained.

Furthermore, if metal foil is used as the reinforcing skin material, due to the difference in coefficient of thermal expansion between it and the foamed resin substrate, there is a risk that it will peel off as the temperature rises in the conventional structure where flat objects are bonded together. However, if a recessed groove is provided on the front surface of the foamed resin substrate, that is, on the adhesive surface with the reinforcing skin material as in the present invention, the space within the recessed groove will absorb the thermal strain of both. When the above-mentioned peeling can be suppressed, the same effect can be obtained.

[Brief explanation of the drawing]

1 to 3 show an embodiment of a speaker diaphragm according to the present invention, in which FIG. 1 is a side sectional view, FIG. 2 is a partially cutaway plan view, and FIG. 3 is a different embodiment. FIG. 4 is a side sectional view of a conventional example. 1... Foamed resin substrate, 2... Reinforcing skin material, 4... Recessed groove for degassing.

Claims (1)

[Claims for Utility Model Registration] A speaker diaphragm comprising a reinforcing skin material 2 bonded to the front surface of a foamed resin substrate 1, wherein the reinforcing skin material 2 is a metal foil, and the foamed resin substrate 1 is made of a foamed resin substrate. 1. A diaphragm for a speaker, characterized in that a front surface of the substrate 1 is formed with checkerboard-shaped or radial gas vent grooves 4 that are open to the sides of the substrate 1.