JPH09247789A - Diaphragm for electroacoustic transducer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To secure the airtightness and also to improve the light-weight properties and the reproduced sound pressure by using a material that is obtained by applying the thin filling resin processing to a material that is stitched plain by a special weaving way and undergone the heat press fabrication. SOLUTION: A plain stitch ground part is formed by weaving finely the thin single yarns of polyester fibers undergone the super-drawing treatment as the warps and wefts. Then 2 to 4 single yarns are drawn evenly as warps and the single yarns thicker than the warps are used as wefts. These warps and wefts are woven plain at a rip-stop part with the fixed width space of the ground part secured, and this woven part undergoes the thin filling resin treatment and pressed by a heating metallic die. In such a way, a center dome part 1a, an edge part 1b and a support part 1c are formed by fabrication. In such a constitution of a speaker diaphragm 1, the upper end part of a voice coil bobbin 3 wound round by a voice coil lead wire 3a is adhered to the outer edge part of the part 1a. Then the part 1c is bonded to a magnetic circuit 4, so that the coil 3 is supported in a magnetic gap 4a. Thus it is possible to secure the airtightness, to improve the light-weight properties and the reproduced sound pressure and also to increase a reproduced frequency sound range.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fiber material, which has not been used up to now, and has fine denier fibers finely woven as warp and weft, and is regularly and intermittently bundled or thick. A special weaving method in which single yarns are laid in lengthwise and widthwise and weaved, there are few pinholes, thin thickness, light weight, high density, high Young's modulus, high propagation speed, and high internal loss. The present invention relates to a speaker diaphragm having physical properties.

[0002]

2. Description of the Related Art Conventionally, this kind of speaker diaphragm has been made by weaving a plain weave material made of natural fibers such as cotton and silk having the same thickness as warp threads and weft threads into a phenol resin for hardness adjustment. It was impregnated and solidified by heating to form a preform, which was then coated with acrylic resin or urethane resin and sealed to form a diaphragm.

[0003]

Therefore, in the conventional speaker diaphragm of this type, the original rigidity of the fiber is not so large, and the rigidity of the diaphragm is maintained by the rigidity due to the solidification of the resin. Therefore, the thickness of the resin becomes the thickness of the diaphragm as it is, the Young's modulus is small, and since the phenol resin is used, the internal loss (tan δ) value does not become large. Since the propagation velocity of was small, the reproduced sound pressure frequency range was narrow and resonance occurred as a vibration mode. And when incorporated in a speaker, the mass of the diaphragm is large,
There was also a problem that the conversion efficiency was low and the reproduced sound pressure was low.

Therefore, in order to solve the problems that the conventional diaphragm for a speaker has, the diaphragm of the present invention has the elongation of the fiber of the material composing the diaphragm which is usually about 50 of that of the polyester yarn. In order to increase the tensile strength and to reduce the elongation by performing ultra-stretching so that the amount becomes 100%, the weaving method is different from the conventional method, and fine denier fibers are densely driven into the plain weave. With a special woven method in which fibers with a thick denier value are arranged intermittently and regularly between them, and high tension is applied to the threads to weave, and Young's modulus, propagation speed, and internal loss as a speaker diaphragm are achieved. It is intended to provide a diaphragm for a speaker, which has a high conversion efficiency and can improve the reproduced sound pressure by making it lightweight with the aim of retaining an optimum value. It is.

[0005]

The structure of the present invention for achieving the above object will be described with reference to FIGS. 1 to 5 corresponding to the examples. The polyester fiber 2 super-stretched to 60% or less is used as warp yarns 2a and weft yarns 2b, and the ground portion is formed by driving the warp yarns 2a and the weft yarns 2b at a regular ratio of the numbers of the warp yarns 2a and 2b. With a certain width in the transverse direction, 2 to 4 single filaments of the above-mentioned ultra-stretched polyester fiber are aligned as the warp threads 2c of the ripstop portion, and 2 to 4 filaments are aligned as the weft threads 2d of the ripstop portion. Or a single yarn thicker than the above single yarn, intermittently,
In addition, the material which is regularly struck and arranged and made into a plain weave is treated with a resin for sealing with a basis weight of 20 g / m ² or less, and then heated directly by the heated male and female dies 5a and 5b. It is a diaphragm for electroacoustic transducer that is pressed and molded.

Further, in the present invention, the polyester fiber 2 super-stretched to have an elongation of 60% or less of that of a normal polyester yarn is used as warp yarns 2a and weft yarns 2b, and the ratio of the number of striking them is regular. 30 to 50 denier of the above-mentioned super-stretched polyester fiber with a constant width of 5 to 7 filaments / in in the longitudinal direction and 5 to 7 filaments / in in the lateral direction of the gland portion. / 15 to 25 filament single yarn as the warp yarn 2c of the rip stop portion
4 pieces are aligned, and 2 to 4 threads of 30 to 50 denier / 15 to 25 filaments are aligned as the weft thread 2d of the rip stop portion, or a single thread of 100 to 140 denier / 20 to 30 filaments, Heated male and female metal molds 5a, 5b, each of which is intermittently and regularly hammered in and arranged and plain woven material 2 is subjected to a resin processing treatment for sealing with a basis weight of 20 g / m ² or less, and heated. It is a vibration plate for an electroacoustic transducer that is directly heated and pressed by being brought into close contact with and molded.

Since the present invention has such a structure, the following operational effects can be obtained.

That is, (1) Since the ground portion of the diaphragm 1 of the present invention is densely struck with the fine ultra-stretched polyester fibers and flat knitted as described above, the material cloth material 2 is thin. The high areal density can be maintained. Therefore, the thin fibers 2
The amount of urethane resin coating for sealing that deteriorates its properties as a vibration plate because there are few pinholes and air leakage does not occur because the gap between a and 2b and between the thick fibers 2c and 2d is narrow and airtightness is maintained. It is possible to perform a resin processing treatment that reduces the number of times and the number of times.

(2) Further, as described above, the fibers of polyester having a thin denier value are arranged in a row in a row, and the fibers are 20 g / m 2.
^{Since the} resin is processed with a small basis weight of ² or less,
Lightweight finish, high conversion efficiency as a speaker,
The speaker diaphragm 1 has a high reproduced sound pressure and an improved sound pressure of about 2 to 3 dB as compared with the conventional example.

(3) Further, the vibrating plate 1 of the present invention can maintain the Young's modulus of the cloth 2 as high as four times that of the conventional example and the propagation speed thereof is also about two times by the above-mentioned material and processing method. Becomes Thus, despite the high Young's modulus, tan
δ does not decrease and shows a constant different from the physical constant of the conventional diaphragm material. This is made by finely woven polyester fine fibers whose Young's modulus has been remarkably increased by performing the above-mentioned super-drawing processing without performing resin processing using a conventional impregnating agent such as phenol resin. This is due to the nature of the cloth 2.

[0011]

[Table 1]

Table 1 is a list of physical properties such as density, Young's modulus, propagation velocity, and internal loss of the diaphragm material of the present invention, polyester cloth material, wood pulp, and various diaphragm materials such as polypropylene.

As a result, the material 2 of the diaphragm 1 of the present invention is
Since the material thickness is reduced to about 1/2, that is, the internal loss as a cloth material is 1.4 times, and the internal loss (ta
nδ) is large, Young's modulus as a sheet material is large,
It can be said that a good balance can be maintained as a diaphragm material.

Further, in the diaphragm 1 of the present invention, the sound wave propagation velocity is approximately doubled and the piston vibration range of the diaphragm is doubled for the above-mentioned reason, and the frequency of the harmonic vibration having a clear vibration pattern is increased. Is getting higher. Therefore, the peak and dip of the sound pressure frequency characteristic are small and the characteristic becomes flat, and the high frequency limit frequency becomes higher, and the reproduction frequency range becomes wider.

(4) As described above, since the diaphragm 1 of the present invention has the airtightness and the high Young's modulus as the sheet material 2, it has the bending resistance and the abrasion resistance as the diaphragm. With a large amplitude and withstanding a large amplitude against a large electrical input,
Mechanically long life can be maintained. Further, when the urethane resin is used for the edge of the diaphragm 1 such as a soft dome, it is easy to radiate a high sound, the material durability is increased, and deterioration is less likely to occur.
The reliability of the speaker can be improved.

(5) Further, the diaphragm 1 of the present invention can be manufactured by the physical properties of the material and its processing even under the severe use condition of the speaker.
Since it can retain heat resistance, humidity resistance, water resistance, chemical resistance, and gas resistance, it retains weather resistance (environmental resistance) and retains shape retention even in a harsh environment, with shape restitution, The shape retaining property can be secured, and the qualitative change does not occur as the vibration plate, so that the qualitative life can be maintained for a long time.

[0017]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 5 are views showing an embodiment of the present invention. FIG. 1 is a cross-sectional view in which a voice coil is attached to an embodiment of the diaphragm of the present invention, and FIG. 2 is an enlarged view of the cloth of the embodiment. FIG. 3 is an exploded view, FIG. 3 is a cross-sectional view of a speaker equipped with the diaphragm of FIG. 1, FIG. 4 is a cross-sectional view of a thermal mold for molding the diaphragm, and FIG.
FIG. 3 is a cross-sectional view showing a mode in which a speaker equipped with the diaphragm of the present invention is attached to a baffle plate.

The conventional dome-shaped diaphragm will be described by taking a dome-shaped diaphragm as an example. Usually, the dome-shaped diaphragm is formed in a dome shape, and a voice coil bobbin around which a voice coil is wound is attached to the dome-shaped diaphragm so that the inside of a magnetic gap of a magnetic circuit is attached. Attached to and functions as a speaker. A speaker (FIG. 3) equipped with the dome-shaped diaphragm of FIG. 1 will be described.

Conventionally, however, a dome-shaped diaphragm is formed by impregnating a cloth such as cotton with phenolic resin, etc., and after drying, heats and solidifies the resin by using male and female heat dies and pressurizes it. The center dome portion, edge portion, and support portion of the plate are molded.

Next, the upper end of the bobbin around which the voice coil is wound is adhered to the outer edge of the dome portion, and the above-mentioned supporting portion is attached to the magnetic circuit or screwed to complete the mounting. Then, as shown in FIG. 5, the baffle plate is attached by making attachment holes. In the case of the cone type diaphragm, the paper pulp fiber is made into a cone shape, shaped, and the voice coil bobbin is attached to the tip thereof, and is attached to the magnetic circuit in the same manner as described above.

As shown in FIG. 2, the diaphragm 1 of the present invention comprises 40 polyester fibers which have been super-stretched so that the elongation of the fibers constituting the diaphragm is usually about 50% of that of polyester yarn. Fine fibers with a small denier value of about denier / 20 filaments are used as warp threads 2a, respectively.
Knitting a flat knitted ground part by striking 0 yarns / in and a weft yarn 2b with a density of 92 yarns / in, and a constant width of 6 yarns / in warp and 5.5 yarns / in weft. , As the warp threads 3c of the lip stop, respectively.
2 to 4 fibers of 0 denier / 20 filament are aligned, and monofilament of 125 denier / 24 filament is driven in as the weft thread 2d of the lip stop portion, and is super-drawn at a draw ratio of about 50% of normal thread as a whole. Material 2 made of plain polyester woven fabric with a basis weight of 20 g /
Male and female molds 5a, 5 which have been treated with a thin sealing resin of m ² or less and heated with heating wires 6, 6 etc. as shown in FIG.
This is the speaker diaphragm 1 in which three parts, that is, the central dome portion 1a, the edge portion 1b, and the support portion 1c of the diaphragm 1 are molded by being brought into close contact with b and being directly heated and pressed.

Then, after separating from the molds 5a and 5b, the upper end of the voice coil bobbin 3 having the voice coil conductor 3a wound around the outer edge of the dome portion 1a as shown in FIGS. After bonding, the supporting portion 1c is attached and attached to the magnetic circuit 4 so that the voice coil 3a is supported in the annular magnetic gap 4a of the magnetic circuit 4, and is completed. Then, as shown in FIG. 5, a mounting hole 8a is formed in the baffle plate 8 and the dome portion 1a is mounted so as to be exposed to the outer surface.

In this way, when a voice input current is input to the voice coil 3a conducting wire, the voice current flowing through the voice coil 3a is induced with the magnetic flux in the magnetic gap 4a to cause vibration in accordance with the voice input, and the voice is input. To occur.

Although the embodiments considered to be representative of the present invention have been described above, the present invention is not necessarily limited to the structures of these embodiments, and has the above-mentioned constitutional requirements of the present invention, and It is suitable for other electroacoustic transducer parts such as a diaphragm of a cone type speaker, an edge material, or a dust cap, which is appropriately modified within a range that achieves the object of the invention and has the following effects. ,
What can be done to them.

[0025]

As apparent from the above description, the diaphragm 1 of the present invention has an elongation of about 50% of that of polyester yarn.
The fine fibers of polyester that have been subjected to ultra-stretching so as to be A thin filling resin of 20 g / m ² or less made from a plain weave material with a special weaving method in which monofilament fibers having a large denier value are intermittently and regularly arranged and woven as a lip stop portion. Since it is processed and molded by hot pressing, it has a remarkable effect which cannot be expected from the conventional ones as described below.

(1) In the diaphragm 1 of the present invention, the material cloth material 2 has a small thickness and can maintain a high density (see Table 1). Therefore, since the gaps between the fibers 2a, 2b and 2c, 2d are narrow and airtightness is maintained, air leakage does not occur, and pinholes after molding are small, so that the material dough 2 does not spread.

(2) By processing a dilute resin having a small basis weight, the finish becomes lighter and the reproduction sound pressure is high as a high-efficiency speaker, and the reproduction sound pressure is 2 to 3 as compared with the conventional example.
Improves dB.

(3) The Young's modulus of the fabric of the diaphragm of the present invention is
The height can be maintained as high as four times that of other conventional examples, and the propagation velocity is also about double (see Table 1). Although the material is thin, the internal loss as a cloth material is 1.4 times that of other materials, the tan δ is large, the Young's modulus as a sheet material is large, and a good balance as a diaphragm material can be maintained. A speaker using the diaphragm of the present invention has flat sound pressure frequency characteristics with less peaks and dips, and thus has less reproduction distortion, and has a higher high limit frequency and a wider reproduction frequency range. Become.

(4) Since the diaphragm of the present invention has bending resistance and wear resistance due to its airtightness and high Young's modulus, it has a large vibration amplitude and can withstand a large amplitude against a large electric input. Mechanically long life can be maintained.

(5) The diaphragm of the present invention has heat resistance, humidity resistance,
It has water resistance, chemical resistance, gas resistance, and maintains weather resistance (environmental resistance), so shape retention can be maintained even in harsh environments, and shape restoration and shape retention can be secured. Since the diaphragm does not change qualitatively, it has the effect of maintaining a qualitatively long life.

The present invention has been described above by taking the dome-shaped diaphragm as an example of the material having the above-mentioned characteristics. However, by using the same material, the cone-shaped diaphragm, the dust cap, and the edge can be used. It can also be applied as a material or a constituent material for electroacoustics such as a headphone constituent part.

[Brief description of drawings]

FIG. 1 is a cross-sectional view in which a voice coil is mounted on an embodiment of a diaphragm of the present invention.

2 is an enlarged exploded view of the fabric of the embodiment in FIG. 1. FIG.

3 is a cross-sectional view of a speaker equipped with the diaphragm of FIG.

FIG. 4 is a cross-sectional view of a male-female heating mold for molding a diaphragm.

FIG. 5 is a cross-sectional view in which a speaker equipped with the diaphragm of the present invention is attached to a baffle plate.

[Explanation of symbols]

 1 Diaphragm 1a Dome part 1b Edge part 1c Support part 2 Fabric 2a Vertical fiber of ground part 2b Horizontal fiber of ground part 2c Vertical fiber of lip stop part 2d Horizontal fiber of lip stop part 3 Voice coil bobbin 3a Voice coil 4 Magnetic circuit 4a Toroidal magnetic air gap 5a Male mold 5b Female mold 6 Heating wire 8 Baffle plate 8a Mounting hole

Claims (2)

[Claims] 1. A polyester fiber 2 which has been super-stretched so that its elongation is 60% or less of that of a normal polyester yarn.
As the warp yarns 2a and the weft yarns 2b to form a gland portion by regularly striking the ratio of the number of the embeddings. Thread the warp 2 of the ripstop
2 to 4 yarns are aligned as c, and 2 to 4 yarns are aligned as the weft yarn 2d of the rip stop portion, or a single yarn thicker than the single yarn is intermittently and regularly driven. , Placed in a plain weave material and weighing 20 g /
A vibrating plate for an electroacoustic transducer, which has been subjected to molding processing by subjecting it to a resin processing treatment for sealing of m ² or less and bringing it into close contact with heated male and female molds 5a and 5b. 2. A polyester fiber 2 which has been super-stretched so that its elongation is 60% or less of that of a normal polyester yarn.
As the warp yarns 2a and the weft yarns 2b to form a gland part by making the ratio of the number of these pegs regular, and 5 to 7 yarns / in in the longitudinal direction and 5 to 7 yarns / in the lateral direction. 3 of the above-mentioned ultra-stretched polyester fiber with a constant width of in
0-50 denier / 15-25 filament single yarn,
Align 2 to 4 warp threads 2c in the ripstop,
Further, as the weft thread 2d of the rip stop portion, two to four yarns of 30 to 50 denier / 15 to 25 filaments are aligned, or a single yarn of 100 to 140 denier / 20 to 30 filaments is intermittently, respectively. In addition, it is driven in regularly and arranged in a plain weave material 2 with a basis weight of 20 g.
A vibrating plate for an electroacoustic transducer, which has been subjected to a resin processing treatment for sealing of not more than / m ² and is brought into close contact with the heated male and female dies 5a and 5b to be directly heated and pressed to be molded.