JP2591839Y2 - Speaker unit - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a speaker unit having a plate-like damper member.

[0002]

2. Description of the Related Art Generally, a general speaker unit used for an audio device such as a stereo is constructed as shown in FIG. As shown in FIG.
Has a pot-shaped yoke 3 in which a columnar magnet 2 is disposed inside, and a housing 4 expanded in a substantially conical shape is provided with a bolt or the like via a top plate 5 at the front end thereof. Is fixed by

[0003] Inside the housing 4, a conical diaphragm 7 whose peripheral portion is supported at the tip end of the housing 4 by an edge 6 made of an elastic member is provided so as to float above the inner wall of the housing. A hollow cylindrical voice coil portion 8 is mounted at the center of the conical diaphragm 7 so as to penetrate therethrough. A voice coil 9 is wound around a base portion of the voice coil portion 8, and a driving current is supplied to the voice coil 9. Is configured to flow.

A portion of the voice coil 9 of the hollow cylindrical voice coil portion 8 is disposed on the outer periphery of the tip of a columnar pole piece 10 made of a magnetic material connected to the magnet 2 and is slightly separated therefrom. The voice coil 9 is mounted so as to vibrate in the axial direction. When a driving current is applied to the voice coil 9, the voice coil unit 8 and the diaphragm 7 connected thereto are vibrated accordingly to emit sound. Has become.

A plate-shaped damper member 11 as shown in FIG. 6 is provided on the base side of the housing 4 to connect the voice coil unit 8 to the base. 9 is configured to be positioned with respect to the pole piece 10 and exhibit a damper function for the diaphragm 7. Specifically, the damper member 11
As shown in FIG. 6, a ring-shaped outer ring is formed by punching out, for example, one bake plate, and is attached to the inner wall of the housing 4 via a height adjusting member 12 such as laminated paper. A ring-shaped inner ring portion 14 attached and fixed to the outer periphery of the voice coil portion 8 with an adhesive or the like;
And an arm 15 that connects between the two. As shown in FIG. 6, two sets of the arm parts 15 are provided symmetrically with respect to each other at an interval of 180 °.
Is composed of a straight arm portion 15A extending linearly inward from the outer ring portion 13 and a pair of curved arm portions 15B developed on both sides of the straight arm portion 15B, for example, and an end portion of both curved arm portions 15B. Are connected to the inner ring portion 14.

In FIG. 5, reference numeral 16 denotes a cap,
Is a sound absorbing material provided in the yoke 3. In such a configuration, when a driving current is passed through the voice coil 9, the voice coil section 8 and the diaphragm 7 connected thereto are driven by electromagnetic induction acting between the voice coil 9 and the magnet 2.
In addition, the damper member 11 vibrates and emits sound.

[0007]

In the loudspeaker unit having the above structure, not only the diaphragm 7 but also the damper member 11 vibrate at the same time during operation. There is a problem that the vibration occurs at an unnecessary resonance frequency other than the resonance frequency, and a sound field faithful to the original sound cannot be reproduced.

This will be described in detail. 7 is a diagram showing the damper member 11 shown in FIG. 6 in an abstract manner, and FIG. 8 is a diagram equivalently showing the vibration mode of the damper member shown in FIG. As shown in FIG. 7, at the center of the damper member 11, a vibration system combined mass M including the entire weight of the diaphragm 7 and the voice coil unit 8, and at the center of each curved arm portion 15B, the mass of the damper curved portion. m is shown as being located, and of the straight arm 15A and the curved arm 15B, a portion connected to the vibration system combined mass M side and a portion connected to the straight arm 15A are respectively shown. The stiffness of
It is represented as S ₀ , S ₁ , and S ₂ , and has a function as a resilient member as shown in FIG. Here, by supplying the driving current to the voice coil, the vibration system combined mass M
Vibrates at the resonance frequency f ₀ of the speaker, and also vibrates at the unnecessary resonance frequency f _D due to the stiffness of the curved arm portion 15B.

At this time, the resonance frequency f ₀ and the unnecessary resonance frequency f _D of the speaker are expressed by the following equations. f ₀ = (S / M) ^1/2 · 1 / 2π f _D = (S _D / m) ^1/2 · 1 / 2π where S is the combined stiffness of each stiffness S ₀ , S ₁ , S ₂ ( N / m), and _SD is the composite stiffness of the _two stiffnesses S ₁ and S ₂ , that is, the stiffness of the curved arm portion. FIG. 9 shows the frequency characteristics of the speaker unit at this time. In the figure, a curve A1 is a sound pressure curve,
Curve A2 indicates an impedance curve. In FIG. 9, the horizontal axis is a logarithmic scale. As shown in the drawing, both the sound pressure curve A1 and the impedance curve A2 generate an unnecessary resonance at a frequency f _D , for example, 320 Hz, in addition to the main resonance at a frequency f ₀ , for example, 55 Hz.

As described above, when the damper member 11 in which the linear arm 15A and the curved arm 15B are combined is used, unnecessary resonance always occurs. The present invention focuses on the above problems, and has been made to solve the problems effectively. The purpose of the present invention is to eliminate unnecessary resonance by making the damper member a simple structure. It is to provide a speaker unit.

[0011]

According to the present invention, in order to solve the above problems, the inside is connected to a voice coil unit for vibrating the diaphragm, and the outside elastically supports the diaphragm. In a speaker unit having a damper member connected to a housing, the damper member includes an inner ring portion connected to the voice coil portion, an outer ring portion connected to the housing, and one end connected to the inner ring portion. And a curved arm portion having the other end inscribed and connected to the outer ring portion.

[0012]

According to the present invention, as described above, when the voice coil unit vibrates, both the diaphragm and the damper member connected thereto vibrate. In this case, since the inner ring portion and the outer ring portion of the damper member are connected tangentially by, for example, a curved arm portion formed in an arc shape, vibration in a mode different from the main resonance does not occur, and unnecessary resonance occurs. Can be suppressed.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the speaker unit according to the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 is a plan view showing a damper member used in the speaker unit according to the present invention, FIG. 2 is a view showing an abstraction of the damper member shown in FIG. 1, and FIG. 3 is equivalent to the vibration mode of the damper member shown in FIG. FIG.

The damper member 18 shown in FIG. 1 supports the voice coil portion of the speaker unit so as to always maintain a loosely fitted state on the pole piece connected to the magnet, and has a damper function for the amplitude plate. This is installed at the same location as the conventional damper member 11 of the speaker unit 1 shown in FIG.

As shown in the figure, the damper member 18 is formed by punching out a single bake plate having a thickness of, for example, about 1 mm. The damper member 18 is formed by cutting the inner wall of the conical housing 4 shown in FIG. A ring-shaped outer ring portion 19 attached via a height adjusting member 12 such as a laminated paper, and a ring-shaped inner ring portion 20 attached and fixed to the outer periphery of the voice coil portion 8 with an adhesive or the like.
And an arm portion 21 connecting the two ring portions 19 and 20 to each other.

In this embodiment, three arm portions 21 are formed, and each arm portion 21 is tangentially extended at an equal interval of 120 ° from the outer periphery of the inner ring portion 20 while being extended at equal intervals. The curve reaches the inner circumference of the outer ring portion 19 with the same curvature (arc) or while gradually changing the curvature. Further, a portion where the arm portion 21 and the outer ring portion 19 are connected is such that an end of the arm portion 21 extending in a curved shape is in a tangential direction of the ring-shaped outer ring portion 19. Therefore, the arm 21 as a whole is formed in a spiral shape around the inner ring 20. The curvature of the arm portion 21 is determined based on the distance between the inner ring portion 20 and the outer ring portion 19, and the number of the arm portions 21 is limited to three as in the illustrated example. Instead, for example, four or more may be provided.

As described above, the entire arm portion 21 is formed into a spiral curved shape, and is connected to the outer periphery of the inner ring portion 20 so as to circumscribe and to the inner periphery of the outer ring portion 19 so as to be inscribed. Therefore, when the vibration mode during the speaker operation is considered by simplifying the structure, it is not necessary to consider the extra mass that becomes the vibration center in the middle of the arm portion 21, and as shown in FIG. 2 and FIG. Only the vibration system combined mass M that generates resonance and the stiffness S of the damper member 18 and the elastic edge 6 of the diaphragm 7 need to be considered, and generation of unnecessary resonance can be suppressed.

Next, the operation of the embodiment constructed as described above will be described. First, a driving current is applied to a voice coil 9 provided at the base end of the voice coil unit 8, and the voice coil unit 8 and a diaphragm connected to the voice coil unit 8 are actuated by electromagnetic induction acting between the voice coil 9 and the magnet 2. 7
In addition, the damper member 18, which is a feature of the present invention, vibrates and emits sound (see FIGS. 1 and 5). The vibration mode at this time is represented as shown in FIG. 2 and FIG.
It is not necessary to consider an extra mass that becomes a vibration center in the middle of the arm 21.

That is, the main resonance frequency f _{0 of the} speaker
Is expressed as follows in the same manner as described above. f ₀ = (S / M) ^1/2 · 1 / 2π where S is the combined stiffness (N / m) of the entire vibration system,
M is the combined mass of the entire vibration system. The combined stiffness S of the entire vibration system includes the edge stiffness S _E of the diaphragm and the combined stiffness S _D of a damper member having three arms, and the combined mass of the entire vibration system includes a voice coil unit. In addition to the mass of the vibration system such as the diaphragm 8 and the diaphragm 7, additional mass such as air resistance is included.

At this time, the composite stiffness S of the damper member
_D is singly expressed as follows, and it is not necessary to consider stiffness that causes unnecessary resonance. S _D = a · E · d · t ³ / l

Here, a is the number of the arm portions (3 in this embodiment), d is the width of the arm portion, t is the thickness of the damper member,
E is the Young's modulus, l is the effective length of the arm, and is given by the following equation. l ≒ (φ1−φ2) π / 2 where φ1 is the inner diameter of the outer ring portion 19 and φ2 is the outer diameter of the inner ring portion 20.

As described above, the entire arm portion 21 is formed in a spiral curved shape for simplification, so that only vibration at the resonance frequency f ₀ of the speaker is generated, and unnecessary resonance which has conventionally occurred is generated. Generation can be suppressed, and the sound field of the original sound can be faithfully reproduced.

FIG. 4 shows the frequency characteristics of the speaker unit at this time. In the figure, a curve B1 indicates a sound pressure curve, and a curve B2 indicates an impedance curve. In FIG. 4, the horizontal axis is a logarithmic scale. As shown, sound pressure curve B
1. Both the impedance curve B2 and the main resonance at the frequency f ₀ (for example, 55 Hz) hardly cause resonance, and almost no resonance occurs at the frequency 320 Hz where unnecessary resonance occurs in the conventional device. Turned out not to be.

In the above-described embodiment, the damper member formed in a circular ring shape corresponding to the diaphragm 7 formed in a conical shape has been described. However, the present invention is not limited to this. It goes without saying that the present invention can be similarly applied to a damper member formed into, for example, an elliptical ring or another shape corresponding to the above.

[0025]

As described above, according to the speaker unit of the present invention, the following excellent effects can be obtained. Connect the arm of the damper member to the inner ring
Circumscribed or inscribed with the outer ring part
Direction, and formed into a simple curved shape that extends spirally , so that unnecessary resonances other than the main resonance can be suppressed, and therefore, a sound field faithful to the original sound can be reproduced. .

[Brief description of the drawings]

FIG. 1 is a plan view showing a damper member used in the speaker unit according to the present invention.

FIG. 2 is a diagram showing an abstraction of the damper member shown in FIG. 1;

FIG. 3 is a diagram equivalently showing a vibration mode of the damper member shown in FIG. 2;

FIG. 4 is a graph showing frequency characteristics of the speaker unit according to the present invention.

FIG. 5 is a sectional view showing a general speaker unit.

FIG. 6 is a plan view showing a damper member of a conventional speaker unit.

FIG. 7 is a diagram showing an abstraction of the damper member shown in FIG. 6;

8 is a diagram equivalently showing a vibration mode of the damper member shown in FIG.

9 is a graph showing frequency characteristics of a conventional speaker unit using the damper member shown in FIG.

[Explanation of symbols]

1 speaker unit, 2 magnet, 3 yoke,
4 housing, 6 edge, 7 diaphragm, 8 voice coil section, 9 voice coil, 18 damper member, 19
... outer ring part, 20 ... inner ring part, 21 ... arm part.

Claims (1)

(57) [Scope of request for utility model registration] 1. A speaker unit having a damper member having an inner side connected to a voice coil unit for vibrating a diaphragm and an outer side connected to a housing for elastically supporting the diaphragm. An inner ring portion connected to the voice coil portion, an outer ring portion connected to the housing, one end of which is circumscribed and connected to the inner ring portion, and the other end of which is inscribed in the outer ring portion. Connected and from the inner ring portion to the
A speaker unit comprising a plurality of curved arm portions spirally extending to an outer ring portion .