JPH0744154Y2 - Speaker diaphragm - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention mainly relates to improvement of a diaphragm of a dome-shaped speaker.

<Prior Art> For example, in a conventional direct-radiation dome-shaped diaphragm, concavo-convex wrinkles are formed all over the diaphragm as in Japanese Patent Publication No. 31-653, and the thickness of the vibration surface is reduced. Then, there is a structure in which elasticity is enhanced by reducing the mass.

<Problems to be solved by the invention> However, in the diaphragm as described above, since the concentric concavo-convex portions are continuous, resonance easily occurs and many peaks and valleys of the sound pressure frequency characteristic occur, and The reproduced sound has many distorted sounds, especially in the high range.

Such resonance of the vibrating plate in the vicinity of the treble limit frequency is likely to cause distortion in the high frequency range because the vibrating plate mainly causes concentric divided vibrations and radiates.

In order to eliminate such drawbacks, the present invention symmetrically forms arc-shaped recesses (2) that do not make a full circle in order to eliminate the peak sound that is heard in the treble near the treble limit frequency in the treble range.
It is a dome-shaped diaphragm (1) which is suppressed so that concentric resonance does not occur.

<Means for Solving the Problems> The structure of the present invention for achieving the above object will be described with reference to FIGS. 1 to 5 corresponding to the embodiments. Symmetrically arcuate recess (2)
Is provided.

Then, the end face (3) parallel to the axis of the recessed portion (2) of the dome-shaped diaphragm (1) made of a thin metal plate in FIGS. 1 and 2 is an arc-shaped curved surface concentric with the axis, The end surface parallel to the axis of the recessed portion (2) of the diaphragm (1) in FIGS. 5 to 6 is flat.

<Operation> According to the present invention, the vibration radius is constant in the reproduction vibration frequency band in which the diameter of the recessed portions (2) and (2) of the dome-shaped diaphragm (1) formed by the above means is half the wavelength. Since no standing wave is generated, the symmetry of vibration is broken, and concentric divisional vibration does not occur, so no audible resonance sound is generated and distortion sound in the treble reproduction limit range is eliminated.

<Embodiment> Referring to FIGS. 1 to 6 showing an embodiment, the arc-shaped recesses (2) and (2) having the same radius are made to face each other in the vicinity of the outer edge of the dome-shaped diaphragm (1). Are provided symmetrically. The end face (3) of the recess (2) is parallel to the axis,
The bottom surface (4) is perpendicular to the axis. Thus, the dome-shaped vibrating portion is formed of the same material, and the entire dome-shaped vibrating portion is continuously formed. The diaphragm for a speaker is formed so that the upper and lower surfaces of the plate are not vented. At that time, at a frequency of a wavelength substantially equal to the diameter of the arcuate recess (2), the vibration stiffness is different in the circumferential direction, so that the resonance force is dispersed and the peak due to the significant resonance on the sound pressure frequency characteristic is Does not happen. The width, height, length and position of the recessed portion can be freely selected according to the type, shape, thickness, Young's modulus, strain type to be removed, etc. of the composition material of the diaphragm (1). it can.

In a dome-shaped diaphragm (1) with a diameter of 78 mmφ formed by forming a thin diaphragm material plate, it generally depends on the Young's modulus (E / ρ) of the material, but generally it is a stationary state derived from the outer diameter near 3,000 Hz. Wave resonance occurs, but in order to remove such distorted sound, if arc-shaped recesses (2) and (2) are formed on the circumference of a diameter of about 4,25 cm, a standing frequency of 3,000 Hz Since the wave resonance force is damped on the concave portions (2) and (2), the distorted sound near the intended 3,000 Hz can be removed as shown in the frequency characteristic diagram of FIG.

The material of the dome-shaped diaphragm is generally aluminum,
Aluminum alloys such as duralumin, metal thin plates such as titanium, and synthetic resin thin plates such as phenolic or polypropylene are often used, but in the present invention, it is difficult to adjust the physical properties such as Young's modulus of the metal thin plate described above. Therefore, it is easy to apply and has a large effect.

The present invention has been described below with reference to the representative examples of the present invention, but the present invention is not necessarily limited to only the structures of these examples.
The present invention can be appropriately modified and carried out within a range that achieves the object of the present invention and has the following effects.

<Effects of the Invention> Since the present invention has the above-mentioned configuration, the recesses (2), (2) formed symmetrically on the metal dome-shaped diaphragm (1).
By virtue of this, since the vibration mode of the diaphragm (1), particularly the divided vibration in the high frequency range does not occur intensively, it is possible to reduce the distortion due to the divided resonance in the high frequency range, and
Since the same material is used and the entire surface is continuous, the sound pressure on both the front and back sides of the diaphragm is not short-circuited, so that the sound pressure is not short-circuited and the efficiency of the speaker is not reduced.

The present invention can be used as a diaphragm for a horn type speaker facing the equalizer since there is no protrusion on the upper surface of the diaphragm plate for a metallic speaker.

[Brief description of drawings]

FIG. 1 is a plan view of a speaker diaphragm of the present invention, FIG. 2 is a side view of the same, FIG. 3 is a sectional view of a speaker incorporating the speaker diaphragm, and FIG. 4 is a conventional example (shown by a dotted line). FIG. 5 is a plan view of a speaker diaphragm according to another embodiment, and FIG. 6 is a side view of the same. In the figure, (1) is a diaphragm, and (2) is a recess.

Claims (1)

[Scope of utility model registration request] 1. A dome-shaped vibrating part is formed of the same material, and the entire surface is continuous. The upper and lower surfaces of the plate are provided so as not to vent, and the end surface (3) of the recess (2) is formed by a thin metal plate having a shape parallel to the axis and a bottom surface (4) perpendicular to the axis. A diaphragm for a dome-shaped speaker (1).