JPS6348240B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention has appropriate compliance with respect to the force in the axial direction of the voice coil bobbin, good linearity even at large amplitudes, and furthermore, has a high degree of compliance with respect to the force in the direction perpendicular to the axis of the voice coil bobbin. The purpose of the present invention is to provide an electrodynamic speaker equipped with a damper that has a sufficient regulating force against the vibration and improves the rolling strength of the vibration system of the speaker.

FIG. 1 shows a conventional general electrodynamic speaker. In FIG. 1, 1 is a yoke with a center pole 2 integrally formed, 3 is an annular magnet fixed on the yoke 1, and 4 is an annular plate fixed on the magnet 3. An annular magnetic gap is formed between the inner peripheral surface and the center pole 2. 5 is a frame fixed on the plate 4, and 6 is a diaphragm. The outer circumference of the diaphragm 6 is supported by the frame 5 via an edge member (not shown). 7 is the diaphragm 6
A voice coil bobbin 8 is wound around the coil bobbin 7 . Reference numeral 9 denotes a wave-shaped damper made by impregnating cloth with resin and molding it by heating, and the inner circumference of this damper 9 is
It is fixed to the coil bobbin 7, and the outer periphery is attached to the frame 6.
is fixed. 10 is a dust cap attached to the diaphragm 6.

In the conventional electrodynamic speaker described above, the damper 9 restricts the movement of the coil bobbin 7 in a direction perpendicular to the axis thereof, and the coil bobbin 7 moves in the axial direction.

The conditions required for the damper 9 that holds the coil bobbin 7 are (a) appropriate compliance in the axial direction of the coil bobbin and good linearity even at large amplitudes, (b) diameter of the coil bobbin It must have sufficient stiffness in the direction, etc.

However, since the corrugated damper 9 in the conventional example has a sufficiently high stiffness in the radial direction of the damper 9 to satisfy the condition (b) above, the condition (a) above is not satisfied, and as shown in FIG. As shown by A in Fig. 1, there was a drawback that the force-displacement characteristics of the damper 9 became non-linear when the amplitude was large. Therefore, in conventional speakers, harmonic distortion occurs in the low frequency range.

However, an electrodynamic speaker equipped with a damper that can eliminate the above-mentioned conventional drawbacks has been proposed. Next, the damper of this electrodynamic speaker will be explained with reference to FIGS. 3 to 5.

3 to 5 show the damper 11 in the electrodynamic speaker. This damper 11
is constructed by bonding two damper plates 12 and 13 together at necessary locations. Each damper plate 12, 13 has the same shape, and has a rectangular central support part 15a, 15b in which a hole 14a, 14b into which a coil bobbin is inserted and fixed is formed, and an outer periphery of each central support part 15a, 15b. Bent parts 16a, 16
four damper pieces 17a connected via b,
17b, 17c, 17d, 18a, 18b, 18
c, 18d Each damper piece 17a to 17d, 18a
It is composed of outer peripheral support parts 20a and 20b connected to the outer periphery of ~18d via bent parts 19a and 19b, and the central support parts 15a and 15b of the two damper plates 12 and 13, and the outer peripheral support parts 20a and 20
b are pasted together. Each of the damper pieces 17a to 17d, 18a to 18d has two surface elements 22a, 22b, 23a connected via the bent portions 21a, 21b parallel to the bent portions 16a, 16b and the bent portions 19a, 19b. , 23b, each surface element 22a, 22b, 23a, 23
A reinforcing rib is formed on b to increase the rigidity of the surface. The damper pieces 17a to 17d made up of the surface elements 22a and 22b are bent so as to be convex upward, and the damper pieces 18a to 18d made up of the surface elements 23a and 23b are bent so as to be convexed downward,
As shown in FIG. 4, the surface elements 22a, 22b, 23
When viewed from the side, a and 23b form a quadrilateral. 24
This is a dustproof net whose inner periphery is held between central support portions 16a and 16b, and whose outer periphery is held between outer periphery support portions 20a and 20b.

FIG. 6 shows the operation of the damper, where solid lines indicate a stationary state and broken lines indicate an upwardly displaced state. Surface elements 22a, 22b, 23a,
23b constitutes quadrilaterals a, b, c, and d,
When the coil bobbin fixed to the central support section is displaced upward, point c is displaced to point c in the direction of axis l of the coil bobbin, and quadrilaterals a, b, c, and d are transformed into quadrilaterals.
a′, b′, c′, d′. Point c is displaced in the direction of axis l,
The damper pieces 1 on both sides of the damper pieces 17a and 18a are not displaced in the direction perpendicular to the axis l.
This is because it is regulated by 7b, 18b and 17d, 18d. According to the damper shown in FIGS. 3 to 5, as shown by B in FIG.
It vibrates with good linearity even at large amplitudes.

In the damper described above, two damper plates of the same shape are bonded together, but the center support portion and the outer peripheral support portion of one damper plate may be removed. In addition, although the above-mentioned damper is provided with four sets of bendable and extensible rectangular cylinders made of four surface elements, it is sufficient to provide a rectangular cylinder at each outer periphery of the regular polygonal central support portion.

However, even in the above conventional examples, the rolling strength was not sufficiently improved. The reason for this will be explained below with reference to FIGS. 7a and 7b.

FIGS. 7a and 7b show the area elements 22b and 23b and the outer peripheral support parts 20a and 20 of the damper shown in FIGS. 3 to 5.
The vicinity of the bent portions 19a and 19b between FIG. As shown in FIGS. 7a and 7b, in the conventional example, reinforcing ribs 25a and 2 formed on the surface element 22b are
Since there are flat portions 26a, 26b between the end portion of 5b and the bent portions 19a, 19b, the flat portions 26a, 26b are bent, and the rolling strength is not improved.

As shown in FIG.
A flat portion 26a extending to b and shown in FIGS. 7a and b,
A prototype damper was produced in which 26b was removed, but this had the drawback of poor linearity.

Further, the present inventor has discovered that, as shown in FIGS. 9a and 9b,
Curved corrugations 27a and 27b on the flat part
In this case, when the damper operates, a force along the planes 22b and 23b acts, and the corrugations 27a and 27b
was deformed, and the rolling strength was not improved.

The present invention eliminates the above-mentioned conventional drawbacks and improves linearity and rolling strength. An embodiment of the present invention will be described below with reference to FIGS. 10a and 10b.

In Figures 10a and 10b, 28a and 28b are
Curved corrugations, 29a, 2 formed in the direction along the bent portions 19a, 19b at the ends of the surface elements 22b, 23b on the bent portions 19a, 19b side.
9b is a reinforcing rib having a triangular cross section formed on the surface elements 22b and 23b, and this reinforcing rib 29a and 29
The orientation of the three parallel edges L, M, and N of b is the bending part 1.
The reinforcing ribs 29a, 29b are oriented perpendicularly to each other, and one ends of the reinforcing ribs 29a, 29b are connected to the curved surfaces of the corrugations 28a, 28b. These reinforcing ribs 29a, 29b are connected to surface elements 22b, 2
When forming a plurality of surface elements 22b, 2b,
The rigidity of 3b is increased and the rolling strength is improved.

In the above embodiment, the corrugation 28 is provided only on the bent portions 19a, 19b side of the surface elements 22b, 23b.
a, 28b, but surface elements 22a, 23
A similar corrugation may be formed only on the bent portions 16a and 16b of a, or a corrugation may be formed on both sides.

The present invention has the above-mentioned configuration, and as the rigidity of the surface elements increases and a flexible hinge without rattling is constructed, the linearity and rolling strength of the damper are improved, and the large amplitude region below f ₀ is improved. This eliminates distortion and allows for expanded low-frequency playback.

[Brief explanation of the drawing]

Figure 1 is a sectional view of the main parts of a conventional electrodynamic speaker, Figure 2 is a force-displacement characteristic diagram of a damper of a conventional electrodynamic speaker, and Figure 3 is a damper of another conventional electrodynamic speaker. The top view of Figure 4 is A- of Figure 3.
OB arrow view, FIG. 5 is a perspective view of the damper, FIG. 6 is an explanatory diagram of the operation of the damper, FIGS. 7a and b are sectional and perspective views of the main parts of the damper, and FIG. 8 FIGS. 9a and 9b are cross-sectional views and perspective views of the main parts of another damper, and FIGS. 10a and 10b are cross-sectional views of the main parts of the damper of an electrodynamic speaker according to an embodiment of the present invention. FIG. 2 is a diagram and a perspective view. 7...Coil bobbin, 8...Voice coil, 1
1... Damper, 12, 13... Damper plate, 1
4a, 14b...hole, 15a, 15b...center support part, 16a, 16b...bend part, 17a-17
d, 18a to 18d... damper piece, 19a, 1
9b...Bending part, 20a, 20b...Outer peripheral support part, 21a, 21b...Bending part, 22a, 22
b, 23a, 23b...plane element, 28a, 28b...
...corrugation, 29a, 29b...reinforcement ribs, L, M, N...ridge.

Claims (1)

[Claims] 1. A regular polygonal central support portion in which a hole into which a coil bobbin is inserted and fixed is formed, and a plurality of bendable and extensible rectangular cylinders connected to each outer periphery of the central support portion via bending portions; An outer peripheral support part connected to the outer peripheral part of the square cylinder via a bent part, and at least one side of the center support part side and/or the outer peripheral support part side of the surface elements forming the square cylinder body. a curved corrugation formed along the bent portion, and a reinforcing rib having a triangular cross section formed in the area and having a plurality of ridges in a direction perpendicular to the bent portion; An electrodynamic speaker comprising a damper in which an end of a reinforcing rib is connected to a curved surface of the corrugation.