JPH02195800A - On-vehicle speaker frame - Google Patents

Abstract

PURPOSE:To improve sound effect by suppressing oscillation in a frame itself by forming the frame by using a damping metallic plate in which thermosetting resin is interposed between plural metallic plates and they are unified. CONSTITUTION:An on-vehicle speaker frame 1 is formed by using the damping metallic plate 2 in which a single layer of thermosetting resin 4 is interposed between two sheets of metallic plates 3a and 3b. Therefore, superior rigidity can be maintained by the metallic plates 3a and 3b, and also, the oscillation can be suppressed by the function of the thermosetting resin 4, which improves dynamic rigidity, and also, resonance can be suppressed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a speaker frame for a vehicle that suppresses vibrations of the frame itself and improves acoustic effects.

[Conventional technology]

Speaker frames for attaching vibration systems and magnetic circuits are generally made of press-formed and plated steel plates, or drawn-formed steel plates.

In terms of acoustic effects, such a frame is required not to resonate or tremble when the diaphragm vibrates, and this also applies to in-vehicle use.

Therefore, attempts have been made to suppress the resonance phenomenon by increasing the thickness and weight of the plates that make up the frame, by molding the frame with a material that has 100% vibration properties, or by pasting damping materials on the frame. .

Furthermore, a frame using a damping steel plate with a viscoelastic material containing polyisobutylene or diolefin hydrocarbon resin sandwiched between two metal plates has also been proposed.
3-113396).

[Problem to be solved by the invention]

However, increasing the thickness of the frame in order to increase the rigidity of the frame is not only uneconomical, but also increases weight, which impairs the moldability of the frame itself.

Also, how to attach vibration damping material to the frame.

There are inconveniences such as misalignment or falling off due to long-term use.

In particular, in-vehicle speakers are installed on the inside of the front and rear doors of a car, on the front panel, or on the rear parcel tray, but when it comes to the inside of the door, the installation location itself is in an extremely closed space. Therefore, the temperature of the vehicle body itself increases due to direct sunlight, resulting in an extremely high temperature environment.In the case of a rear parcel tray, in addition to the same temperature conditions as above, the front part of the speaker is exposed to direct sunlight through the rear glass. As a result of being exposed to heat, the temperature of the speaker itself increases significantly, and there is a strong tendency for the damping material to shift or fall off.

On the other hand, the damping frame disclosed in Japanese Utility Model Application Publication No. 63-113396 solves the above-mentioned problem of increased weight. Because the speaker itself is placed in an extremely high temperature environment due to rising temperatures, etc., the resin sandwiched between multiple metals may leak out or melt/soften, and the steel plate may peel off, making it impossible to maintain its original performance. However, there are many problems in practical use, such as the inability to withstand long-term use.

The disadvantages of the frame made of damping steel plates are due to the fact that the viscoelastic body sandwiched between the steel plates is a thermoplastic resin.

This invention was made to solve problems such as ridges, and allows speakers to be mounted without increasing the weight of the frame itself, even when the speaker is mounted in a position exposed to extremely high heat. It can be used for a long period of time without deteriorating its performance. The purpose of this invention is to provide an in-vehicle speaker frame that prevents resonance phenomena.

[Means to solve the problem]

In order to achieve the above object, the in-vehicle speaker frame of the present invention has a frame formed using vibration-damping metal plates that are integrally formed by sandwiching a thermosetting resin between a plurality of metal plates.

What is the simplest form of frame 1 of this invention?

As shown in FIG. 2, a damping metal plate 2 is used, which is made by interposing a single layer of thermosetting resin 4 between two metal plates 3a and 3b.

The metal plates 3a and 3b used may be steel plates, or a combination of different metal plates may be used.

Although not shown in the drawings, it may also be one in which three or more metal plates are laminated and integrated with a thermosetting resin interposed between them.

The metal plate used in this invention is a steel plate.

Aluminum plates, stainless steel plates, titanium plates, and other metal plates can be used, and there are no special restrictions on their thickness, but those with a thickness in the range of approximately 0.1 to 1.5 mm should be used. It is preferable.

Moreover, the thickness of the two sheets may be the same or different.

On the other hand, the thermosetting resin interposed in this metal plate is
Although there are various types, 9 for example, an acrylic resin that hardens by causing a crosslinking reaction when heated can be used.

The thermosetting resin is applied between the metal plates by 0.02 to 0.0.
It is desirable to interpose it so that it has a thickness of 15 m.

The thus obtained distributed metal plate is punched and drawn into various shapes such as circular, elliptical, and square in accordance with ordinary speaker frame forming methods, and then a diaphragm, spider, voice coil, magnet, A speaker can be easily formed by attaching pole pieces, plates, etc.

[For production]

The in-vehicle speaker frame of this invention uses metal plates to maintain excellent rigidity comparable to conventional speaker metal frames, and the resin sandwiched between the metal plates suppresses vibration and improves dynamic rigidity. At the same time, resonance is suppressed.

Since damping steel plates made of thermosetting acrylic resin have excellent vibration distribution and high damping characteristics, it is possible to obtain speakers with significantly reduced harmonic distortion.
It is possible to obtain a high-quality speaker that is capable of crisp, high-fidelity playback, can withstand large digital sound inputs, produces clear sound quality, and reproduces deep bass.

Furthermore, since the resin is thermosetting, there is very little deterioration even during long-term use, even at the temperatures to which the vehicle-mounted speaker is exposed, resulting in a speaker that has both high reliability and excellent sound quality.

〔Example〕

This invention will be described in more detail below with reference to Examples and Comparative Examples.

As shown in FIG. 2, a steel plate 3 a + with a thickness of 0.511
3b, a damping metal plate 2 sandwiching a thermosetting acrylic resin 4 having a modulus of elasticity shown in FIG. 3 with a thickness of 0.05 m is punched and drawn to form a 6 inch×
A 9-inch two-way elliptical vehicle-mounted speaker frame 1 was molded, and a magnetic circuit (not shown) and a vibration system (not shown) were attached to this speaker frame 1 to obtain a vehicle-mounted speaker.

On the other hand, a two-way elliptical speaker frame for a vehicle having the same shape as the embodiment is formed using a steel plate having the same thickness (1.0 ins) as the vibration-damping metal plate 2 and the same material as the steel plates 3a and 3b, A car speaker was obtained in the same manner (Comparative Example 1)
.

FIG. 4 shows the results of measuring vibration damping waveforms under the same conditions for the speakers of these examples and comparative examples.

As is clear from FIG. 4, the in-vehicle speaker frame shown in the example has approximately five times the attenuation as compared to the in-vehicle speaker frame shown as a comparative example, and it is clear that the damping metal plate It can be seen that the in-vehicle speaker using the in-vehicle speaker frame of the present invention has excellent dynamic rigidity.

Furthermore, when the acoustic output characteristics were measured, the results shown in FIG. 5 were obtained.

As is clear from FIG. 5, the in-vehicle speaker frame of the example has a maximum of 10 dB reduction in second- and third-order harmonic distortion, and has excellent acoustic effects.

When actually playing music, the car speaker using the car speaker frame of the example has a much sharper and clearer sound than the car speaker using the car speaker frame of the comparative example. I got good sound quality.

Moreover, the in-vehicle speaker frame of the present invention is as follows.

Even in a heat environment of 110° C. for 2 hours under the heat resistance test conditions for a vehicle-mounted speaker, there was no change at all in both the external appearance and the thickness change measured with a micrometer.

Naturally, no change in sound quality was observed in measurements of second- and third-order harmonic distortion.

〔Effect of the invention〕

The in-vehicle speaker frame of the present invention is constructed using a distributed metal plate made of thermosetting resin, so it has excellent vibration energy absorption performance of the frame and sufficiently eliminates harmonic distortion, making it possible to It has the effect of providing far superior sound quality compared to speakers, and at the same time maintaining the heat resistance required for in-vehicle speakers.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing an embodiment of the in-vehicle speaker frame of the present invention, Fig. 2 is a cross-sectional view of the distributed metal plate used in the in-vehicle speaker frame of the above embodiment, and Fig. 3 is the distributed metal plate of the embodiment. It is a figure showing Young's modulus of the thermosetting resin used for a board. Figure 4 is a diagram showing the vibration damping characteristics of the in-vehicle speaker frames of the example and comparative example, and (a) shows the case of the example.
(b) shows the case of a comparative example. FIG. 5 shows the output characteristics of the in-vehicle speakers of the example and the comparative example, where (a) shows the case of the example and (b) shows the case of the comparative example. 2... Vibration damping metal plates 3a, 3b... Metal plate 4... Thermosetting resin

Claims (1)

[Claims] An in-vehicle speaker frame characterized in that the frame is formed using a vibration-damping metal plate formed by sandwiching and integrating a thermosetting resin between a plurality of metal plates.