JPH0712236B2 - Composite speaker - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a composite speaker used for various audio equipment.

Configuration of Conventional Example and its Problems With the development of audio equipment in various fields in recent years, the performance required for a speaker has been diversified, especially in the field of car audio. A relatively large number of compound speakers are used in this car audio system, which is a method with many merits, such as the fact that a single multiway is possible and the sound image localization becomes clear.

This composite type speaker is roughly divided into two types, one for fixing the high-frequency speaker in the space in front of the woofer with a bridge such as a resin gasket, and the other for fixing it to the upper end of the support rod connected to the center of the upper surface of the woofer magnetic circuit. There is a street.

FIG. 1 shows a typical conventional example. That is, a ring-shaped magnet 3 and an upper plate 4 are assembled on a plate 2 having a center pole 1 to form a magnetic circuit 5, a frame 6 is coupled to this magnetic circuit 5, and a gasket 7 is attached to the periphery of the frame 6 together with a gasket 7. A voice coil 10 is formed by connecting a cone diaphragm 8 and a voice coil 10 whose middle portion is supported by a damper 9 at the center of the cone diaphragm 8.
Is inserted into the magnetic gap 11 of the magnetic circuit 5 without eccentricity to form a bass speaker 12.
A support rod 13 is erected on the 12 center poles 1, a high-pitched speaker 14 is attached to the upper end of the support rod 13, and a dustproof damper 15 is attached to the bottom of the high-pitched speaker 14 and an intermediate portion of the cone diaphragm 8. It was pasted and configured. Here, the problems particularly occur are the support rod 13 on the magnetic circuit 5 and the cone diaphragm 8
It is a dustproof damper 15 that connects the. Most of these are formed by forming a cloth having several concentric corrugations as shown in the figure, and are generally called dustproof dampers due to the shape. The dustproof damper 15 prevents dust from entering the magnetic gap 11 from between the support ratio 13 and the voice coil bobbin, but at the same time, the performance of the bass speaker 12 is significantly deteriorated. That is, the dustproof damper 15
If the diameter of the cone diaphragm 8 is small, the amplitude of the cone diaphragm 8 is limited, the low-range resonance frequency o rises, and harmonic distortion due to the amplitude non-linearity occurs. The sound pressure is decreased due to the increase, the abnormal noise is generated due to the abnormal resonance of the dustproof damper 15 itself, and the frequency characteristic is deteriorated.

Furthermore, when the adhesion portion between the dustproof damper 15 and the cone diaphragm 8 is relatively displaced (due to dimensional accuracy, deformation, and assembly accuracy of each component), the vibration system receives asymmetrical stress and causes more strain. To occur.

Further, in assembly, abnormal noise is generated due to defective adhesion between the dustproof damper 15 and the cone diaphragm 8 and accounts for a large proportion of defects.

Incidentally, FIG. 2 shows a conventional example as an improvement plan of FIG. This uses a polymer foam body 16 instead of the cloth dustproof damper 15, and although it is improved as compared with FIG. 1, increase of o and generation of strain due to the elongation limit and outer diameter of the foam body 16 However, the abnormal sound of a single body is unavoidable, and the reliability problem due to the pull strength and the like remains.

An object of the present invention is to provide a composite speaker having a dustproof mechanism that solves the problems in the conventional composite speaker as described above.

In order to achieve the above object, the composite speaker of the present invention is
A bass speaker is formed by coupling a diaphragm to the periphery of a frame coupled to the magnetic circuit, and coupling a voice coil that fits into the magnetic gap of the magnetic circuit to the center of the diaphragm. The loudspeaker is fixed to the upper end of the support rod connected to the center of the upper surface of the magnetic circuit of the loudspeaker, and the cylindrical soft polymer foam is attached to the upper end of the support rod or the bottom of the high-pitched loudspeaker, and its lower end to It is constructed by sticking to the center of the voice coil or the vibrating plate in the vicinity of it, and expanding the cylindrical soft polymer foam to the outer periphery in the stationary state of the speaker. A great dustproof effect can be obtained.

Description of Embodiments One embodiment of the present invention will be described below with reference to FIGS. 3 and 4.

First, in FIG. 3, reference numeral 17 denotes a bass speaker, and this bass speaker 17 is a plate having a center pole 18.
A frame 23 is coupled to a magnetic circuit 22 constructed by incorporating a ring-shaped magnet 20 and an upper plate 21 on the frame 19, and a gasket 24 and a cone-shaped diaphragm 25 are provided around the periphery of the frame 23.
The peripheral portion of the vibration coil 25 is fixed by adhesion or the like, and the middle portion of the diaphragm 25 is fixed to the voice coil 27 by the damper 26.
And the lower part of this voice coil 27 is connected to the above magnetic circuit 22.
The magnetic gap 28 is fitted into the magnetic gap 28 without being eccentric.

The center pole 18 of the magnetic circuit 22 of the bass speaker 17
A support rod 29 made of synthetic resin or the like is coupled to the upper surface of the
A treble speaker 30 is fixed to the upper end of the support rod 29.

Further, the upper end of a cylindrical soft polymer foam 31 such as foamed polyurethane is bonded to the upper end of the support rod 29 or the bottom surface of the high frequency speaker 30 by adhesion, and the lower end thereof is a voice coil of the low frequency speaker 17. It is bonded to the upper end of 27 or the central portion of the diaphragm 25 near the voice coil 27 by adhesion or the like.

Here, as the dustproof material, a soft polymer foam 31 having good air circulation is molded or die-cut into a cylindrical shape. The upper end of the dust-proof soft polymer foam 31 is adhered to the upper end of the support rod 29 or the bottom of the high frequency speaker 30, and the lower end thereof is adhered to the bobbin of the voice coil 27 or the center of the diaphragm 25 near the bobbin. It Further, this cylindrical polymer foam 31 is fixed so as to have an appropriate bulge on the outside as shown in FIG. 3 in a stationary state where no input is applied to the speaker. This may be performed at the time of molding, or may be performed by deforming the long vertical cylindrical body at the time of bonding.

The dust-proof mechanism according to the present invention is controlled by the amplitude of the vibration plate 25
It works as shown. That is, when the diaphragm 25 moves forward, the polymer foam 31 expands and deforms to the outside as shown in FIG. 4a, and at the stationary reference position, the state shown in FIG. 4b, when moving backward. As shown in FIG. 4c, the outward swelling is reduced to cause elongation and follow the amplitude.

EFFECTS OF THE INVENTION According to the dustproof mechanism of the present invention, the dustproof function can be imparted by the above-described operation with almost no effect on the amplitude and frequency characteristics of the bass speaker. Further, the dustproof material itself does not make an abnormal sound, and the increase in mass is slight. Even when compared with the example of FIG. 2, the expansion / contraction function does not depend on the elongation of the material but on the amount of deformation, so that the stress applied to the diaphragm is very small.
Further, since the cylindrical soft polymer foam swells to the outer periphery in a speed stationary state and both ends thereof are fixed, there is no frictional noise and the dust-proof reliability is high.

Further, since the cylindrical soft polymer foam of the present invention has no sound and the deformation direction is perpendicular to the sound wave direction, it is significantly smaller than the conventional example in which the characteristics are adversely affected by the movement.

Below is a 14 cm round composite speaker with the structure shown in Fig. 1,
An example in which distortion is reduced by comparison with the composite speaker of the embodiment of the present invention will be shown.

Change of total harmonic distortion at o o = 70Hz Conventional structure of Fig. 1 This embodiment of Fig. 3 No.1: 12.2% No.1: 7.1% No.2: 12.0% No.2: 6.6% No. 3: 12.4% No.3: 8.0% * However, in JIS-BOX, Mic distance = 31.6 cm, input = 10 W (6
ΩSPK, 70Hz, 8V)

[Brief description of drawings]

FIG. 1 is a half sectional view showing a conventional composite speaker using a dustproof damper, FIG. 2 is a half sectional view of a conventional composite speaker using an improved dustproof mechanism, and FIG. 3 is a composite speaker of the present invention. FIG. 4 is a half sectional view showing an embodiment of the present invention, and FIGS. 17 …… Bass speaker, 18 …… Center pole, 19 ……
Plate, 20 ... Magnet, 21 ... Top plate, 22
...... Magnetic circuit, 23 ...... Frame, 24 ...... Gasket, 25
...... Cone-shaped diaphragm, 26 …… Damper, 27 …… Voice coil, 28 …… Magnetic gap, 29 …… Support rod, 30 …… High frequency speaker, 31 …… Cylindrical soft polymer foam.

Claims (1)

[Claims] 1. A bass speaker configured by connecting a diaphragm to a peripheral portion of a frame connected to a magnetic circuit, and connecting a voice coil that fits into a magnetic gap of the magnetic circuit to a central portion of the diaphragm. The speaker for high frequencies is fixed to the upper end of the support rod connected to the center of the upper surface of the magnetic circuit of the bass speaker, and the cylindrical soft polymer foam with high air permeability is attached to the upper end of the support rod. Alternatively, a composite type loudspeaker is fixed to the bottom of a treble speaker, the lower end of which is fixed to a voice coil bobbin or a central portion of a diaphragm near the voice coil bobbin, and a cylindrical soft polymer foam is expanded to the outer periphery in a stationary state of the speaker.