JP2002325295A - Damper for speaker, its manufacturing method, and speaker using the damper - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a speaker damper comprising a speaker used in various types of audio equipment, the manufacturing method, and the speaker using the damper. SOLUTION: The periphery of this speaker damper is impregnated with a resin of great bending strength (a second thermosetting resin 16) so that the outer part can become less flexible than the inner part in order to prevent the excessive amplitude which may cause abnormal sounds.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a speaker damper as a support member constituting a speaker used in various kinds of audio equipment, a method of manufacturing the same, and a speaker using the same.

[0002]

2. Description of the Related Art Recently, with the trend of miniaturization and high performance, there has been a demand for a speaker capable of reproducing heavy bass with the spread of high quality sources. In order to enable the reproduction of heavy bass with a small aperture, it is necessary to increase the flexibility of the support system, vibrate the diaphragm of the speaker greatly, and increase the volume velocity, from small input to large input. There is a demand for a vibration-system support component that provides a highly linear amplitude to the driving force generated in the voice coil bobbin, such as a speaker damper.

First, a conventional speaker will be described. FIG. 10 is a sectional view of a conventional speaker. According to FIG. 10, reference numeral 6 denotes a bottom plate 6b having a center pole 6a, a ring-shaped magnet 6c, and a ring-shaped magnet 6c. A magnetic circuit constituted by an upper plate 6e mounted thereon and forming a magnetic gap 6d with the center pole 6a, 7 is a frame mounted on the magnetic circuit 6, and 8 is a frame 7 Edge 8
The diaphragm is connected to the voice coil bobbin 9 whose inner peripheral portion is fitted into the magnetic gap 6d via the magnetic coil 6d.

[0004] Reference numeral 10 denotes a speaker damper for supporting the voice coil bobbin 9 by connecting an outer peripheral portion to the frame 7 and an inner peripheral portion to the voice coil bobbin 9.

Here, the conventional speaker damper 1 is described.
0 will be described in detail with reference to FIGS. FIG. 7 is a plan view and a half sectional view of a conventional speaker damper. According to the drawing, reference numeral 1 denotes a through hole into which the voice coil bobbin 9 is inserted, 2 denotes an inner peripheral edge for coupling the voice coil bobbin 9 around the through hole 1, 3 denotes an outer peripheral edge, Coupled to the frame 7 of the speaker.
4 (4a, 4b, 4c,..., 4n) are formed repeatedly between the inner peripheral edge portion 2 and the outer peripheral edge portion 3 and have an irregular corrugation that makes a round in the circumferential direction. In general, the main material is a cotton cloth or the like which is relatively air-permeable and impregnated with a thermosetting phenolic resin. It is formed.

Next, a deformation mechanism of the above-described conventional speaker damper will be described with reference to FIGS. FIG. 8 is a half cross-sectional view of a conventional speaker damper, in which a shape a at rest and a shape b of the speaker damper when the voice coil bobbin is displaced by −X are overlapped with each other.
(A), (b), (c) is a diagram showing a speaker damper in an equivalent leaf spring configuration.

When the corrugated shape of the speaker damper 10 is the same from the inner peripheral portion to the outer peripheral portion, it is considered that the same degree of flexibility is maintained in the section having a unit width in the circumferential direction. Since the damper 10 has a donut shape in which the voice coil bobbin 9 is fixed to the inner diameter and the outer diameter is fixed to the frame 7, the outer peripheral portion has a smaller flexibility (for example, twice the radius) than the inner peripheral portion in a schematic representation. About half
Below).

That is, FIG. 9A shows that the inner diameter of the corrugated portion is 2b,
FIG. 9B is a plan view of a speaker damper in which several slits 5 are added to a conventional speaker damper having an outer diameter of 2a. FIG. 9B shows one section divided into four by the slit 5 in FIG. It is a diagram represented by a thin plate, and the left end is a portion to be joined to the voice coil bobbin 9, and its width is πb /
2. The right end is a portion to be bonded to the frame 7 and is a fixed end having a width of πa / 2, and the length approximates a trapezoidal shape of ab. FIG. 9 (c) is a representation in which the part protruding from the width πb / 2 of FIG.
This constitutes a stack of three or three leaf springs.

[0009]

As is apparent from the schematic diagram of FIG. 9 described above, this kind of speaker damper has a lower degree of flexibility, that is, becomes harder toward the outer periphery, and the vibration is increased. The displacement in the vibration axis direction per unit length in the radial direction is not evenly distributed to each part in the radial direction. Has a large displacement in the vibration axis direction per unit length in the radial direction, and the outer peripheral portion having a small degree of flexibility does not take much displacement in the vibration axis direction per unit length in the radial direction.

Therefore, the conventional speaker damper is
(1) Even if the joint portion (inner peripheral edge) of the voice coil bobbin vibrates back and forth, sufficient linearity of force-displacement characteristics cannot be ensured, and large displacement cannot be achieved.

(2) A corrugation is formed in the speaker damper in order to obtain a large vibration amplitude. However, an amplitude with good linearity cannot be obtained in the range of the fiber contraction which can be restored, and a small-diameter speaker is used. If the amplitude value is forcibly expanded by applying excessive input to produce a bass sound, abnormal sound may be generated due to the tension of the speaker damper, or a change amount that cannot withstand the vibration amplitude occurs only in the inner peripheral part. (The inner periphery is used to mean the inner part except the outer periphery. However, breakage generally occurs near the inner periphery in the inner periphery. ).

According to the present invention, there is provided a force-displacement characteristic at an amplitude limit, even when a large displacement and a sufficient linearity of a force-displacement characteristic are ensured by solving the above-mentioned problems, even when an excessive amplitude is applied at a large input. It is an object of the present invention to provide a clip that can be softly clipped to improve the abnormal sound caused by the tension of the speaker damper and that is hard to break at the inner peripheral portion.

[0013]

According to a first aspect of the present invention, there is provided a loudspeaker damper according to the first aspect of the present invention, which is formed by repeating an annular convex or concave waveform in a radial direction. In the speaker damper of the present invention, an inner peripheral portion formed by impregnating a base material with a first thermosetting resin that gives a small bending strength to the base material and thermoforming the same, and a second thermosetting resin giving a large bending strength And the vicinity of the outer periphery formed by thermoforming.The flexibility of the vicinity of the outer periphery is set lower than the flexibility of the corrugation on the inner periphery, and large displacement is achieved. An object of the present invention is to provide a speaker damper capable of preventing the occurrence or breakage of abnormal sound by softly clipping the force-displacement characteristic with respect to an excessive amplitude when it is made possible.

According to a second aspect of the present invention, there is provided a damper for a loudspeaker which is formed by repeating an annular convex or concave corrugation in the radial direction. A first thermosetting resin that gives a small bending strength, and a second thermosetting resin that gives a large bending strength, which is thermoset at a relatively high temperature, is impregnated with It is formed by thermoforming the corrugation on the inner periphery at a relatively low temperature and thermoforming the corrugation near the outer periphery at a higher temperature. Only the corrugation near the outer periphery is thermoformed at a higher temperature. By doing so, the degree of flexibility can be set lower than that of the wavy shape on the inner peripheral side, and for an excessive amplitude when a large displacement of the speaker damper is made possible, the force- The displacement characteristics can be softly clipped.

According to a third aspect of the present invention, there is provided a method of manufacturing a wave-shaped speaker damper, which is formed by repeating an annular convex or concave wave shape in a radial direction. At least the first material with low bending strength
Impregnating and drying the thermosetting resin, punching the substrate into a substantially circular shape, and forming a first thermosetting resin having high bending strength on the outer periphery of the substantially circularly punched substrate. A step of impregnating and drying a second thermosetting resin that cures at a higher temperature, and a step of molding the vicinity of the outer periphery to a high temperature, and molding the inner periphery to a lower temperature. The flexibility of the outer periphery can be made lower than that of the wavy shape of the inner periphery, and the force-displacement characteristics can be softly clipped for excessive amplitude when the displacement of the speaker damper is large. By doing so, it is possible to manufacture a speaker damper that prevents generation and breakage of abnormal sound.

According to a fourth aspect of the present invention, there is provided a speaker having at least a magnetic circuit having a magnetic gap, a frame mounted on the magnetic circuit, and an inner peripheral portion directly or indirectly connected to the frame. 2. A voice coil bobbin having a peripheral portion coupled to a voice coil bobbin fitted in a magnetic gap of the magnetic circuit, and an outer peripheral portion coupled to the frame and an inner peripheral portion coupled to the voice coil bobbin to support the voice coil bobbin. Alternatively, a speaker is constituted by the speaker damper according to claim 2, and a speaker having a small diameter and capable of reproducing heavy bass sound can be provided by using the speaker damper.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of a speaker damper according to the present invention will be described below with reference to FIGS.

First, the configuration of the speaker and the form of the speaker damper will be described with reference to FIGS. FIG. 1 is a cross-sectional view of a speaker damper, and FIG. 2A is a cross-sectional view illustrating a deformed state during the same driving, and FIG.
FIG. 3 is a schematic view showing a change amount of the same wave type, and FIG. 3 is a cross-sectional view of a speaker using the speaker damper.

According to the figure, 6 is a magnetic circuit, 7 is a frame, 8 is a diaphragm, 9 is a voice coil bobbin, 10a is an outer peripheral portion connected to the frame 7, and an inner peripheral portion is connected to the voice coil bobbin 9. A speaker damper that supports the voice coil bobbin 9. Details of the speaker damper 10a will be described with reference to FIGS. 1 and 2A and 2B.

In FIG. 1, reference numeral 1 denotes a voice coil bobbin 9
Is a through hole to be inserted, and 2 is an inner peripheral portion for joining the voice coil bobbin 9 around the through hole 1. 3
Is an outer peripheral portion, which is joined to the frame 7 of the speaker. Numeral 4 denotes a concave and convex corrugation which is formed repeatedly between the inner peripheral edge 2 and the outer peripheral edge 3 and makes a round in the circumferential direction. Further, a convex waveform 4c on the outer side, and a convex waveform 4n having a narrow outermost peripheral portion.
And the width of each or concave wave shape (Wa,
Wb, Wc,...) Are the ratio of the width of the wave shape inside the outermost circumference to the width Wa of the wave shape at the innermost circumference is approximately the radius ratio at each top or bottom position, Mold width (W
b, Wc,...) are determined in proportion to the width of the waveform at the innermost periphery. The width Wn of the corrugation at the outermost periphery is set smaller than the width at the inner side.

Further, each corrugated shape has two symmetrical surfaces α and β inclined approximately 45 degrees with respect to the reference plane P, and a front or rear surface having a height equal to the distance between the two planes and the reference plane. It is composed of curved surfaces γ and δ in contact with the surface. This surface γ or δ
Is a curved surface of a small arc in the inner peripheral portion, and the length of the linear portion of the surfaces α and β becomes shorter toward the outer peripheral portion so that the curved surfaces γ and δ
Is a curved surface with a large arc.

Next, dashes are given to the reference numerals of the respective parts after deformation in FIG.
The operation of the loudspeaker damper of the present embodiment will be described with the intersections of C1, C2, C3,...

First, a description will be given of the fact that the flexibility of the inner corrugated portion except for the outermost corrugated portion can be set substantially equal. Here, the intersection is located at the same radius even after the deformation, and assuming that the radial elongation of each corrugation is compensated by the shape deformation of each corrugation, the radius of curvature of the top of corrugation 4a on the inner peripheral portion is It becomes wide and Wa
Spreads to Wa ′ and the height decreases slightly from h0 to ha, but the line segment length La of the cross section does not change. It is considered that the wave shape up to the inside of the outermost part (= referred to as the middle part) has a linear portion whose length is gradually shortened and its curvature is gradually increased, and the shape changes like the inner part. . At this time, the top T
4a shifts by δra = ha × Sinθ in the radial direction,
Since the intersections C1 and C2 with the reference plane do not shift, the amount of change in the innermost frequency type is large at δra at the center as shown in FIG. ing.

The total amount of change in each wave form is proportional to the product of each δr and the line segment length (La, Lb,...) Of the wave form, and therefore the change amount per unit length in the radial direction. Is obtained by dividing the total change amount by the width.
× Sinθ × La / Wa, and the amount of change per unit length in the radial direction can be reduced as the wavy shape of the outer peripheral portion where the height with respect to the width is low and the height after deformation is low can be reduced. It can be set to a substantially inverse ratio.

Since the inclination angle θ is generally smaller at the outer peripheral portion than at the inner peripheral portion, the amount of change in the radial direction at the top portion is further reduced. In addition, when the angle (or differential value) of the tangent at each part of the cross section changes, the inner peripheral portion changes greatly near the top, while the inclination angle gradually changes toward the outer peripheral portion. Makes change easier. Therefore, the flexibility can be increased also in the outer peripheral portion, and the flexibility per unit length in the radial direction of the innermost corrugation and the outermost corrugation is determined by the ratio of the radius at which the top portion at rest comes to a certain radius. Can be set approximately equal to the inverse ratio.

Since the outermost corrugation has a narrower width than the inner corrugation, the height change is small, the radial movement is large, and the flexibility per unit length in the radial direction is set low. it can. Therefore, at the stage where the waveform of the inner peripheral portion has extended to the limit due to the large amplitude vibration, the waveform of the outermost peripheral portion is further deformed, and the amplitude-vibration is performed, thereby gradually limiting the force-displacement characteristic.

From the above, when the joint (the inner peripheral edge 2) of the voice coil bobbin 9 vibrates back and forth in the vibration axis direction, the wavy portion excluding the outermost peripheral portion has a short circumference from the inner circumference to the circumference. By setting the degree of flexibility in each part up to the long outer part to be approximately equal, the amplitude value is distributed proportionally and evenly, the entire flexible part is deformed, and a large displacement and a straight line with sufficient force-displacement characteristics are obtained. In the case of excessive amplitude, it is possible to softly clip the force-displacement characteristic at the amplitude limit at the outermost wavy part of the amplitude to improve the abnormal sound due to the tension of the speaker damper, and to improve the inner circumference. Accordingly, it is possible to provide a speaker damper that does not break at the same time.

FIG. 4 is a characteristic diagram showing the relationship between the force and displacement of the speaker damper. FIG. 4 (a) is a characteristic diagram of a conventional speaker damper, and FIG. 4 (b) is the speaker of the above embodiment. It is a characteristic diagram of the damper for use, and as is clear from the figure, the range showing a linear displacement amount is larger than that of the above-described embodiment with l> la, and the displacement amount limit value of the present embodiment is The characteristic near a certain 3 mm point has a steeper rise in the case of the present embodiment, and in the case of the present embodiment, a greater linearity of the force-displacement characteristic can be ensured, and the amplitude can be increased. Also, it was confirmed that by clipping the force-displacement characteristics at the amplitude limit, abnormal sound due to the tension of the speaker damper could be improved, and the speaker damper was hard to break at the inner periphery.

(Embodiment 1) A method of manufacturing a speaker damper according to an embodiment of the present invention will be described with reference to FIG. FIG.
FIG. 5A shows a speaker damper base material 11 obtained by impregnating and drying a first thermosetting resin having a low bending strength, and FIG. 5B shows the speaker damper base material. Reference numeral 11 denotes a damper punched base material 12 obtained in a process of punching the outer diameter and inner diameter holes 13 in a circular shape, which is assumed from a molded product of the speaker damper in advance, and FIG. A guide rod 14 is inserted into the inner diameter hole 13 of the material 12.
The guide rod 14 is rotated and the second thermosetting resin 16 having a large bending strength filled in the container 15 is filled only in the outer peripheral portion of the damper punched substrate 12.
FIG. 6B is a cross-sectional view of a molding die 17 for a speaker damper including a lower die 18a and an upper die 18b. As is clear from the figure, the lower die 18a and the upper die 18 are shown in FIG.
As shown in FIG. 1, the corrugated shape b is widened from the inner peripheral portion to the outer peripheral portion as in the speaker damper 10a in FIG. -It is possible to manufacture a speaker damper having a shape capable of securing the linearity of the displacement characteristic, and the lower die 18a and the upper die 18b are provided with outer peripheral portions 18ao, 18bo and an inner peripheral portion 18a.
ai, 18bi and base portions 21a, 21b,
Outer peripheral portions 18ao, 18bo and inner peripheral portions 18ai, 18
The bi is configured to have a small contact area so as not to conduct heat easily. Heating band heaters 19a and 19b are mounted on outer peripheral side surfaces of the lower die 18a and the upper die 18b, and inner peripheral portions 18ai and 18bi of the die. Has a mold cooling water pipe 20a,
20b is interpolated.

The steps (a) and (b) are carried out by the above-described molding die of the speaker damper having the above-described configuration, in which the outer peripheral portion is controlled to a high temperature (for example, 250 ° C.) and the inner peripheral portion is controlled to a low temperature (for example, 200 ° C.) Through (b) and (c), the obtained entire surface is impregnated with the first thermosetting resin, and then only the outer peripheral portion is further impregnated with the second thermosetting resin. By heat molding, a corrugated portion having a small bending strength is formed on the inner peripheral portion side, and a corrugated portion having a large flexural strength is formed on the outer peripheral portion side.

In the loudspeaker damper formed as described above, only the wave shape near the outermost peripheral portion has a lower flexibility than the inner peripheral portion. In the same manner as when the width is set smaller than that of the inner corrugation, the entire flexible portion (inner peripheral portion) is deformed to secure a large displacement and sufficient linearity of the force-displacement characteristic. With respect to the amplitude, abnormal sound due to the tension of the speaker damper can be improved by softly clipping the force-displacement characteristic at the amplitude limit in the wavy part near the outermost periphery, and for the speaker that does not break at the inner periphery It can provide a damper.

In the above embodiment, the first thermosetting resin which is thermoset with low sound and gives a small bending strength;
A damper punched base material 12 before molding is prepared by selectively setting an impregnated portion of the damper punched base material 12 in an impregnation step with a second thermosetting resin that is thermoset at a high temperature and provides a large bending strength. A speaker damper was manufactured by molding with a mold having a distribution, and a first thermosetting resin which is thermoset at a relatively low temperature and gives a small bending strength;
A damper punched substrate 1 which is thermoset at a relatively high temperature and impregnated with a second thermosetting resin giving a large bending strength.
2 and the same effect can be obtained by molding with a mold having a temperature distribution in which the inner corrugation is set to a relatively low temperature and only the outermost corrugation is set to a high temperature. is there.

In each of the above embodiments, only the outermost corrugation of the speaker damper has been described as having lower flexibility than the inner peripheral side. It is not necessary to limit to only the wave shape, and the flexibility in the vicinity may be set appropriately low.

Further, in the present embodiment, the degree of flexibility in each part on the inner peripheral side from the inner peripheral part having a short circumference to the outer peripheral part having a long circumference in the corrugated part excluding the vicinity of the outermost peripheral part is substantially reduced. Although it is described that the difference in bending strength of the resin impregnated in the speaker damper is used to set the flexibility lower than that of the inner periphery only for the corrugation near the outermost periphery of the speaker damper set equal, Even when utilizing the difference in bending strength of the resin impregnated in the speaker damper to set the flexibility lower only in the wavy shape near the outermost periphery of the speaker damper 10 described in the related art than in the inner periphery. It is also possible to provide a speaker damper that can softly clip the force-displacement characteristic at the amplitude limit due to an abnormally large input at the outermost wavy portion and improve the abnormal sound due to the tension of the speaker damper. It is.

[0035]

As described above, the loudspeaker damper of the present invention provides a loudspeaker damper by softly clipping the force-displacement characteristic at the amplitude limit at the outermost wavy portion for an excessive amplitude. It is possible to provide a speaker damper capable of improving abnormal sound due to the tension, a method of manufacturing the same, and an excellent speaker using the same.

[Brief description of the drawings]

FIG. 1 is a sectional view of a speaker damper according to an embodiment used in the present invention.

FIG. 2A is a cross-sectional view of the same deformation, and FIG.

FIG. 3 is a sectional view of a speaker using the speaker damper.

FIG. 4A shows a force-displacement diagram of the damper for the speaker (conventional); FIG. 4B shows a force-displacement diagram of the embodiment;

5A is a perspective view of a base material of a speaker damper which is impregnated with a first thermosetting resin used for a speaker damper according to an embodiment of the present invention and is dried. Perspective view of punched damper punched substrate

FIG. 6A is an explanatory view illustrating a step of impregnating the second thermosetting resin. FIG. 6B is a cross-sectional view of a molding die of the speaker damper.

7A is a plan view of a conventional speaker damper, and FIG.

FIG. 8 is a modified view of a conventional speaker damper.

9A is a plan view in which slits are added to the speaker damper at several locations for the same explanation. FIG. 9B is a schematic diagram in which one section divided by the slits is represented by a thin plate. Explanatory diagram for explaining with a spring configuration

FIG. 10 is a sectional view of the conventional speaker.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 through hole 2 inner peripheral edge 3 outer peripheral edge 4 corrugated 5 slit 11 base material of speaker damper 12 damper punched base material 13 inner diameter hole 14 guide rod 16 second thermosetting resin 17 molding metal for speaker damper Mold 18a Lower mold 18b Upper mold

Claims (4)

[Claims] 1. A corrugated speaker damper comprising a ring-shaped convex or concave corrugation which is repeated in the radial direction, wherein a base material is impregnated with a first thermosetting resin which gives a small bending strength, and is thermoformed. A speaker damper comprising: an inner peripheral portion formed by the above method; and an outer peripheral portion formed by impregnating and thermoforming a second thermosetting resin giving a large bending strength. 2. A damper for a loudspeaker which is formed by repeating an annular convex or concave corrugation in a radial direction, wherein a first thermosetting which gives a small bending strength by thermosetting a base material at a relatively low temperature. Resin and a second thermosetting resin that gives a large bending strength by thermosetting at a relatively high temperature are mixed and impregnated, and the corrugation of the inner peripheral portion is thermoformed at a relatively low temperature. ,
A speaker damper formed by thermoforming a corrugation near the outer periphery at a high temperature. 3. A corrugated speaker damper formed by repeating a ring-shaped convex or concave corrugation in the radial direction, wherein at least a base material is impregnated with a first thermosetting resin having low bending strength and dried. A step of punching the substrate into a substantially circular shape, and a second step of curing at a higher temperature than the first thermosetting resin having high bending strength near the outer peripheral portion of the substantially circularly punched substrate.
A method of manufacturing a speaker damper, comprising: a step of impregnating and drying a thermosetting resin as described above; and a step of molding a mold heated to a high temperature in the vicinity of the outer periphery and a low temperature in the inner periphery. 4. A magnetic circuit having at least a magnetic gap, a frame mounted on the magnetic circuit, and an outer peripheral portion directly or indirectly coupled to the frame and an inner peripheral portion fitted into the magnetic gap of the magnetic circuit. And a diaphragm coupled to the voice coil bobbin, and a speaker damper according to claim 1 or 2, wherein an outer peripheral portion is coupled to the frame and an inner peripheral portion is coupled to the voice coil bobbin to support the voice coil bobbin. Speaker composed of