JP2018050169A - Speaker component, manufacturing method of the same, and speaker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a speaker component which has a high vibration damping effect and passes well over a wide range with good sound, a method of manufacturing the same, and a speaker.SOLUTION: The speaker component is constituted of a thermoplastic carbon fiber resin base material composed of a composite material containing a thermoplastic resin and carbon fibers. A logarithmic vibration attenuation factor of the composite material is 0.07 to 0.30.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a loudspeaker component that has a high vibration damping rate and transmits clear sound over a wide range and can be subjected to thermal bending, a method for manufacturing the same, and a loudspeaker.

  Conventionally, materials such as wood, metal, fiber, and resin have been selected and used for speaker parts from the viewpoint of ease of shape forming and acoustic performance. In addition, the appearance of the speaker parts is also important. However, depending on the materials used, there are some materials in which the vibration of the generated sound remains as a residual sound for a long time, which overlaps with the next sound to be generated, making it difficult to transmit a clear sound.

  In particular, the residual sound becomes an obstacle when transmitting sounds or human voices over a wide space outdoors. In addition, it is very important to communicate information about lost children at amusement parks and information on time delays and accidents at stations, platforms, bus terminals, and airports. Furthermore, when it is necessary to communicate disaster information such as heavy rain, flood, flash flood, earth and sand disaster, volcanic eruption, pyroclastic flow, mud flow, heavy snow, landslide, avalanche, earthquake, tsunami, fire, nuclear accident, conflict, terrorism, etc. However, a speaker with a residual sound cannot accurately convey disaster information and may not save lives. In particular, outdoor speakers are often regarded as important when electricity, radio, television broadcasting, and the Internet are cut off.

  On the other hand, Patent Document 1 proposes a speaker cabinet made of a sound absorbing material using a synthetic hollow fiber hollow fiber. However, the sound-absorbing material disclosed in Patent Document 1 limits the sound of a specific frequency, and can transmit only a sound that is comfortable to humans to a specific limited place. Not suitable for communicating.

  In this way, when a member specialized in sound absorption is used, information that is originally intended to be transmitted may be limited. Moreover, a lot of electric energy is required to transmit sound far, and many speakers are required. As a result, there is a problem that energy is lost and speakers are crowded in a small area, so that sounds overlap each other and are difficult to hear.

  Patent Document 2 proposes a high damping capacity carbon fiber reinforced resin composite material as a lightweight, high strength, high elasticity material. However, such a thermosetting carbon fiber reinforced resin composite material has many problems in post-processability, and once it is thermally shaped, it is difficult to perform post-processing, and since it does not deform even when heat is applied, Processing is difficult. In addition, when trying to open a large number of through holes in a molded body made of such a carbon fiber reinforced resin composite material, there is a risk of occurrence of cracks, generation of burrs, or short-circuiting of electrical equipment due to carbon fiber dust, Processing by drilling is limited.

  Further, Patent Document 3 proposes a fiber reinforced resin structure composed of aromatic polyamide particles, a matrix resin, and carbon fibers. However, since the fiber reinforced resin structure disclosed in Patent Document 3 has a natural frequency of 100 Hz or more and a loss factor of 0.025 or less, the vibration damping property is insufficient for use in outdoor speakers. It was.

Japanese Patent No. 3007886 JP 7-144371 A JP 2013-203788 A

  The present invention has been made in view of the problems of the prior art, and an object of the present invention is to provide a speaker component having a high vibration damping effect and allowing sound to pass over a wide range, a manufacturing method thereof, and a speaker. is there.

The speaker component of the present invention that achieves the above object has the following configuration.
(1) It is composed of a thermoplastic carbon fiber resin base material composed of a composite material containing a thermoplastic resin and carbon fibers, and the logarithmic vibration damping factor of the composite material is 0.07 to 0.30. Speaker parts to be used.
(2) It is comprised from the thermoplastic carbon fiber resin base material which consists of a composite material containing a thermoplastic resin and carbon fiber, The natural frequency of the said composite material is 10 Hz-60 Hz, and a loss factor is 0.025 or more. This is a speaker component.
(3) The thermoplastic carbon fiber resin base material contains 5% to 60% by weight of the carbon fiber, and the ratio of carbon fiber having a fiber length of 0.01 mm to 0.5 mm in the total carbon fiber is 60. The speaker component according to the above (1) or (2), characterized by being at least wt%.
(4) The thermoplastic carbon fiber resin substrate is a porous sheet having a plurality of through holes, the thickness of the porous sheet is 0.05 mm to 10 mm, and the hole diameter of the through holes is 0.1 mm to 100 mm, The speaker component according to any one of (1) to (3) above, wherein the total opening area of the plurality of through holes is 5% to 75% with respect to the entire surface of the sheet and is a speaker cover.
(5) The speaker component according to any one of (1) to (3) above, wherein the thermoplastic carbon fiber resin substrate has a thickness of 0.05 mm to 2.0 mm and is a speaker cone.
(6) The speaker component according to any one of (1) to (3) above, wherein the thermoplastic carbon fiber resin substrate has a thickness of 0.1 mm to 10.0 mm. .

Moreover, the method for manufacturing the speaker component of the present invention has the following configuration.
(7) A method for manufacturing a speaker component according to any one of (1) to (6) above, wherein the composite material is formed by melt profile extrusion, melt sheet extrusion, injection molding, vacuum molding or blow molding. A method for producing a speaker component, comprising molding the thermoplastic carbon fiber resin substrate.
(8) When cooling the thermoplastic carbon fiber resin substrate, the surface on one side thereof is brought into contact with the metal shaping surface, and the non-contact surface with the metal shaping surface in the thermoplastic carbon fiber resin substrate is used. (7) The method for manufacturing a speaker component according to (7) above, wherein the springback is caused.

Furthermore, the speaker of the present invention has the following configuration.
(9) A speaker comprising the speaker component according to any one of (1) to (6) above.

  According to the speaker component of the present invention, the thermoplastic carbon fiber resin base material has a high vibration damping rate, so there is little residual sound and the sound is clear and can pass sound over a wide range.

It is the perspective view which showed an example of embodiment of the porous sheet of this invention. It is the perspective view which showed an example of embodiment of the speaker cone of this invention. It is explanatory drawing which shows roughly an example of the apparatus used for a vibration damping property measurement. It is explanatory drawing which shows an example of the measurement data of vibration damping property. It is explanatory drawing which plotted the maximum value of the damped vibration waveform of FIG. It is explanatory drawing which shows the measurement result of the vibration damping property in the speaker of Example 1. It is explanatory drawing which shows the measurement result of the vibration damping property in the speaker of the comparative example 1.

  The speaker component of the present invention is composed of a thermoplastic carbon fiber resin base material, and this thermoplastic carbon fiber resin base material is formed of a composite material containing a thermoplastic resin and carbon fibers, a so-called carbon fiber reinforced thermoplastic resin composition. The

  Examples of the carbon fiber constituting the composite material include polyacrylonitrile-based carbon fiber, pitch-based carbon fiber, and rayon-based carbon fiber, and any carbon fiber may be used. The single fiber diameter of the carbon fiber is not particularly limited, but is preferably 5 μm to 10 μm, more preferably 6 μm to 8 μm. The carbon fiber used for the preparation of the carbon fiber reinforced thermoplastic resin composition may be either a long fiber (roving) or a short fiber (chopped strand), but is preferably a short fiber.

  As a thermoplastic resin to be a matrix of the composite material, polyolefin (for example, polyethylene, polypropylene (PP), polybutylene, polystyrene), polyamide (for example, nylon 6, nylon 66, nylon 11, nylon 12, nylon 610, aromatic nylon), polyimide , Polyamideimide, polycarbonate, polyester (for example, polyethylene terephthalate, polybutylene terephthalate, polypropylene terephthalate), polyphenylene sulfide (PPS), polysulfoxide, polytetrafluoroethylene, acrylonitrile butadiene styrene copolymer (ABS), polyacetal, poly Examples include ether, polyether / ether / ketone, and polyoxymethylene. Further, derivatives or modified products of these thermoplastic resins, copolymers of these thermoplastic resins, and mixtures thereof may also be used.

  As the thermoplastic resin, polyamide is preferable, nylon 6, nylon 66, derivatives or copolymers thereof, or a mixture containing at least one of these, more preferably nylon 6, nylon 66.

  In addition, polyolefin is also preferable as the thermoplastic resin, polyethylene, polypropylene, derivatives or copolymers thereof, or a mixture containing at least one of these is more preferable, and polyethylene and polypropylene are more preferable. Further, an acrylonitrile butadiene styrene copolymer, a derivative or copolymer thereof, or a mixture containing the same is also preferable. Furthermore, polyphenylene sulfide, a derivative or copolymer thereof, or a mixture containing any of the above is also preferable.

  The thermoplastic resin may include at least a first thermoplastic resin and a second thermoplastic resin having different viscosities. By including two or more thermoplastic resins having different viscosities, springback can be caused during melt molding. In the present invention, the viscosity of the second thermoplastic resin is preferably 3 to 70 times the viscosity of the first thermoplastic resin at a predetermined high temperature of 20 to 50 ° C. from the melting point of the thermoplastic resin, It is more preferably 50 times, and further preferably 10 to 30 times. The first thermoplastic resin and the second thermoplastic resin are preferably the same kind of thermoplastic resins having different molecular weights and copolymerization components.

  In the above-mentioned speaker component, if one of a high-viscosity resin and a low-viscosity resin is contained in an extremely large amount, the spring back is too large, and tearing and the strength of the sheet itself are reduced. On the other hand, when the resin with a high viscosity is extremely large, the adhesion between the resin and the carbon fiber is poor, which causes cracking. Further, in the melt-kneading using a resin having a high viscosity, the resin temperature rises too much and the resin is decomposed. This tends to be the same for both carbon fiber and glass fiber. In particular, when carbon fiber and high-viscosity resin are mixed, heat generation is high and the glass fiber is easily decomposed. Furthermore, in injection molding, even if a mixture of carbon fiber and resin is injection-molded, it is difficult to produce a thin material because of low fluidity.

  At the same time, even if a resin is made using glass fibers and a resin having high viscosity, the roll surface is damaged when forming into a sheet, and the sheet cannot be continuously produced. In addition, since the fluidity is low, injection molding is difficult. In particular, it is difficult in injection molding of thin materials. Although it is possible to perform injection molding by combining a resin having a low viscosity and glass fiber, it is also difficult to produce a thin material from the viewpoint of fluidity. Therefore, although a product can be obtained by injection molding, since it is inferior in fluidity, only a thick plate of 1 mm or more can be produced, it cannot be produced continuously, and cracks due to welds are likely to occur.

  In the above-described speaker component, the ratio of resins having different viscosities in the thermoplastic carbon fiber resin base material is preferably 0.3 to 5.0 times that the low-viscosity resin is higher than the high-viscosity resin by weight. More preferably, it is 5 to 2.0 times.

  The carbon fiber is preferably 5% by weight to 60% by weight, more preferably 10% by weight to 35% by weight, in 100% by weight of the composite material including the thermoplastic resin and the carbon fiber. By setting the carbon fiber content within such a range, the vibration damping characteristics of the thermoplastic carbon fiber resin substrate can be stabilized.

  The composite material containing the thermoplastic resin and the carbon fiber has a logarithmic vibration damping factor of 0.07 to 0.30. When the logarithmic vibration attenuation rate of the composite material is less than 0.07, the vibration of the speaker component remains for a long time, and the sounds overlap and become difficult to hear. On the other hand, when the logarithmic vibration attenuation rate exceeds 0.30, the vibration of the speaker component is excessively suppressed, and the sound is hardly transmitted. The logarithmic vibration damping rate of the composite material is preferably in the range of 0.08 to 0.30, more preferably in the range of 0.10 to 0.30, and still more preferably in the range of 0.15 to 0.30.

  As the relationship between the logarithmic vibration damping factor and the loss factor, the logarithmic vibration damping factor is equal to the loss factor multiplied by the circumference factor π (logarithmic vibration damping factor = loss factor × π). When the logarithmic vibration attenuation rate of the composite material is five times that of a metal of the same thickness, for example, stainless steel, the vibration of the speaker component using this composite material is 1/5 of the time of the stainless steel material. Shortened to That is, since the remaining sound from the speaker disappears five times faster, the next sound can be heard very clearly.

  On the other hand, since the logarithmic vibration attenuation rate of the metal is smaller than that of the composite material having the same thickness, the vibration of the speaker component made of metal is relatively easy to remain. For this reason, metal parts for speakers have residual sound over a long period of time, so the sound emitted from the speaker is difficult to hear and does not travel far away.

  Further, the speaker component in the present invention is composed of a thermoplastic carbon fiber resin base material made of a composite material including a matrix of thermoplastic resin and carbon fibers made of short fibers, and the natural frequency of the composite material is: 10 Hz to 60 Hz, preferably 10 Hz to 50 Hz.

  When the natural frequency of the composite material is 1/2 of that of a metal having the same thickness, for example, stainless steel, the frequency of vibration of the speaker component using this composite material is 1/2 of that of a stainless steel material. become. That is, the remaining sound from the speaker disappears quickly, so that the next sound can be heard very clearly.

  On the other hand, metal has a higher natural frequency than a composite material having the same thickness, so that high-frequency vibrations are relatively likely to remain in speaker components made of metal. For this reason, metal parts for loudspeakers have high-frequency residual sound, so the sound emitted from the speaker is difficult to hear and does not travel far away.

  Furthermore, in the speaker component according to the present invention, the loss factor of the composite material is 0.025 or more. The loss factor of the composite material is preferably 0.03 or more, more preferably 0.04 or more, further preferably 0.05 or more, and most preferably 0.06 or more.

  When the loss factor of a composite material is 5 times that of a metal of the same thickness, for example, stainless steel, the vibration of the speaker component using this composite material is reduced to 1/5 of the time of a stainless steel material. Is done. That is, the remaining sound from the speaker disappears quickly, so that the next sound can be heard very clearly.

  On the other hand, since metal has a smaller loss coefficient than a composite material having the same thickness, vibrations of speaker parts made of metal are relatively likely to remain. For this reason, since the residual sound remains for a long time in the speaker parts made of metal, the sound emitted from the speaker is difficult to hear and does not travel far away.

  The speaker component of the present invention comprises a thermoplastic carbon fiber resin base material formed of the composite material described above. Since this speaker component can suppress vibration at an early stage, there is little residual sound, and the sound can be transmitted clearly and finely far away. Therefore, the speaker component of the present invention is preferably used for a high resolution speaker or the like. In addition, since it is more resistant to rust than metals and has a long maintenance replacement interval, it can be used for a long period of time. Furthermore, since it is lightweight, it is easy to mount and there is no rust like metal, so the risk of falling from an outdoor high place can be reduced.

  Since the thermoplastic carbon fiber resin base material of the present invention contains carbon fibers, generation of static electricity can be suppressed as compared with a resin product not containing carbon fibers. Therefore, there are few troubles caused by static electricity in winter. Moreover, the thermoplastic carbon fiber resin substrate of the present invention is not easily damaged during punching and has excellent workability. Furthermore, since the base of the thermoplastic carbon fiber resin base material is a thermoplastic resin, it can be easily applied and can be applied regardless of pigments or dyes. In particular, by using a fluorine-containing paint, water resistance and antifouling performance can be improved.

  The speaker component of the present invention can be used as a speaker cover. In that case, as shown in FIG. 1, the thermoplastic carbon fiber resin substrate 1 is a porous sheet 2 having a plurality of through holes 3, and the thickness of the porous sheet 2 is 0.05 mm to 10.0 mm. 3 has a hole diameter of 0.1 mm to 100.0 mm, and the total opening area of the plurality of through holes 3 is preferably 5% to 75% with respect to the area of the entire sheet surface. Furthermore, the thickness of the porous sheet 2 is 0.1 mm to 1.0 mm, the hole diameter of the through hole 3 is 0.5 mm to 5.0 mm, and the total area of the openings of the plurality of through holes 3 is relative to the area of the entire sheet surface. And more preferably 20% to 70%. More preferably, the total opening area of the plurality of through holes 3 is 30% to 60% with respect to the area of the entire sheet surface.

  If the hole diameter of the through hole of the speaker cover is too small, the sound is cut off. If it is too large, the speaker cone or the like is destroyed due to physical influence from the outside. Also, if the aperture ratio of the through hole of the speaker cover (ratio of the total area of the opening of the through hole to the total area of the sheet) is too small, sound is not easily transmitted, and if the aperture ratio is too large, the strength of the speaker cover is maintained. I can't. On the other hand, the pitch of the through holes is the same as the aperture ratio. When the pitch is too wide, the sound is cut off, and when the pitch is too narrow, the strength of the speaker cover tends to decrease.

  Further, as shown in FIG. 2, the speaker component can be used as a speaker cone 4. In that case, the thickness of the thermoplastic carbon fiber resin substrate is preferably 0.05 mm to 2.0 mm. More preferably, it is 0.1 mm-0.5 mm.

  A speaker cone that is as thin as possible is suitable. If the thickness is small, sound is easily transmitted, and a certain thickness is required to maintain a certain level of strength as a speaker cone.

  Furthermore, the speaker component can be used as a speaker housing. In that case, the thickness of the thermoplastic carbon fiber resin substrate is preferably 0.1 mm to 10.0 mm. More preferably, it is 0.3 mm to 2.0 mm.

  The speaker housing is required to be easy to move and light in consideration of installation in a vehicle or high place. At the same time, if the thickness is too thin, the sound tends to leak, so a certain thickness is required.

  In the above-described speaker component, the thermoplastic carbon fiber resin base material contains 5% to 60% by weight of carbon fiber, and the ratio of carbon fiber having a fiber length of 0.01 mm to 0.5 mm in the total carbon fiber. Is preferably 60% by weight or more. More preferably, the thermoplastic carbon fiber resin base material contains 10% to 40% by weight of carbon fiber, and the proportion of carbon fiber having a fiber length of 0.1 mm to 0.4 mm in the total carbon fiber is 60% by weight. % Or more.

  Since the above-described thermoplastic carbon fiber resin base material contains carbon fibers of short fibers in a predetermined ratio, it is possible to maintain sufficient hardness as a speaker component. Further, since carbon fibers having a predetermined range of fiber length are included, it becomes easy to process into a sheet shape. At the same time, post-processing such as vacuum forming, hot pressing or hot bending can be performed.

  Next, a method for manufacturing the speaker component will be described below.

  The speaker component manufacturing method according to the present invention is a method for manufacturing the speaker component described above, wherein the thermoplastic carbon fiber is formed from a composite material by melt profile extrusion molding, melt sheet extrusion molding, injection molding, vacuum molding or blow molding. A resin base material is molded.

  In particular, it is preferable to form by melt sheet extrusion. When the molten sheet is formed by extrusion, post-processing such as vacuum forming, hot pressing, and hot bending can be performed. In addition, a thermoplastic carbon fiber resin substrate having a strength equivalent to that of a metal and having a light weight and a high vibration damping rate can be obtained. Further, by molding a speaker component from this thermoplastic carbon fiber resin base material, a speaker component capable of transmitting clear sound with little residual sound can be obtained.

  In the method for manufacturing a speaker component described above, when the thermoplastic carbon fiber resin substrate is cooled, the surface on one side is brought into contact with the metal shaping surface, and the metal shaping surface in the thermoplastic carbon fiber resin substrate is It is preferable to cause a spring back on the non-contact surface. As a result, the surface of the speaker component is not a uniform mirror surface, but an uneven surface is formed. As described above, the speaker component having an uneven surface has a high vibration suppressing effect.

  In particular, when cooling a thermoplastic carbon fiber resin base material, one side of the surface is brought into contact with the metal shaping surface and rapidly cooled, and the thermoplastic is in a state where a springback occurs on the non-contact surface with the metal shaping surface. More preferably, the carbon fiber resin substrate is solidified. Thereby, more complicated unevenness | corrugation is formed in the surface of the components for speakers, and also an undercut arises. The speaker component having such an uneven surface and having an undercut has a high vibration suppressing effect.

  Finally, the speaker of the present invention will be described. The speaker in the present invention is composed of the above-mentioned speaker component. Moreover, it can also be comprised including in part other than the components for speakers of this invention. Since it is configured by combining the above-mentioned speaker components having high vibration damping properties, it is possible to obtain a high-quality speaker that transmits sound far away without being heard.

  Next, examples will be described. In each example and comparative example, the materials and measurement methods used are as follows.

(1) Materials used (A) Carbon fiber A1: Carbon fiber having a fiber diameter of 7 μm.
(B) First thermoplastic resin B1: Nylon 6 (melting point: 225 ° C., viscosity at 275 ° C .: 80 poise)
B2: Nylon 66 (melting point: 255 ° C., viscosity at 305 ° C .: 250 poise)
B3: PP (melting point: 170 ° C., viscosity at 220 ° C .: 70 poise)
B4: ABS (glass transition point (softening point): 190 ° C., viscosity at 240 ° C .: 120 poise)
B5: PPS (melting point: 285 ° C., viscosity at 335 ° C .: 260 poise)
B6: PC (softening point: 146 ° C., viscosity at 290 ° C .: 125 poise)
(C) Second thermoplastic resin C1: Nylon 6 (melting point: 225 ° C., viscosity at 275 ° C .: 1,100 poise)
C2: nylon 66 (melting point: 255 ° C., viscosity at 305 ° C .: 5,500 poise)
C3: PP (melting point: 170 ° C., viscosity at 220 ° C .: 1,770 poise)
C4: ABS (softening point: 190 ° C., viscosity at 240 ° C .: 2,520 poise)
C5: PPS (melting point: 255 ° C., viscosity at 335 ° C .: 8,060 poise)
C6: PC (softening point: 146 ° C., viscosity at 290 ° C .: 1,890 poise)
(D) Composite material D1: 25% by weight of A1, 50% by weight of B1, and 25% by weight of C1.
D2: 35% by weight of A1, 25% by weight of B1, and 40% by weight of C1.
D3: 20% by weight of A1, 65% by weight of B2, and 15% by weight of C2.
D4: Contains 15% by weight of A1, 45% by weight of B3, and 40% by weight of C3.
D5: 40% by weight of A1, 20% by weight of B4, and 40% by weight of C4.
D6: 40% by weight of A1, 30% by weight of B5, and 30% by weight of C5.
D7: 30% by weight of A1, 30% by weight of B6, and 40% by weight of C6.
(E) Metal E1: Stainless steel (SUS304)

(2) Measurement of fiber length of carbon fiber For measurement of the fiber length of carbon fiber, a microfocus X-ray transmission fluoroscope (SMX-1000 PLUS manufactured by Shimadzu Corporation) was used.

(3) Measurement of vibration damping characteristics The vibration damping characteristics were measured by the test method shown in FIG. This method is based on JIS G0602 (1993). Specifically, it is based on the one-end fixed impact excitation method. The measurement conditions are a cantilever protrusion length of 100 mm, the excitation position is the cantilever free end side, and the excitation method is step relaxation excitation. Measurements were made. Further, as a measuring apparatus, a LK-G30 manufactured by Keyence Corporation was used as a CCD laser displacement meter, and Photon II manufactured by Air Brown Co. was used as an FFT analyzer. Further, for the test piece, a sheet having a thickness of 1.0 mm obtained by the method for producing a carbon fiber composite material disclosed in Japanese Patent No. 5608818 is cut into a size having a thickness of 1.0 mm, a width of 20 mm, and a length of 250 mm. Made.

(4) Calculation of loss factor and logarithmic vibration damping factor The loss factor was calculated by the following formula (1). In addition, the logarithmic vibration damping rate was calculated by multiplying the obtained loss coefficient by the circumferential ratio π.
η = 2 × ln (tan θ) / √ ((2π) ² + [ln (tan θ)] ² ) (1)
In the equation, η is the damping vibration rate, and θ is the slope of a straight line passing through the origin of the graph shown in FIG. 5 is a graph in which the maximum values of the damped vibration waveform of FIG. 4 are plotted. More specifically, the response displacement maximum values X ₀ , X ₁ ... Are read from the damped free vibration waveform shown in FIG. A graph in which the horizontal axis is X _{k + 1} and the vertical axis is X _k , that is, a graph in which points (X ₂ , X ₁ ), (X ₃ , X ₂ ), (X ₄ , X ₃ ). It is.

(5) Calculation of natural frequency The natural frequency was calculated by the following formula (2).
f ₀ = 1 / 2π × √ (k / m) (2)
In the formula, f ₀ is a natural frequency [Hz], k is a spring constant [N / m], and m is a mass [kg].

(6) Evaluation test With 20 healthy listeners as panelists, sound was passed from an evaluation speaker installed outdoors, and an evaluation test was performed on the sound heard at a location 10 m away from the speaker. ◎ (excellent) if the sound emitted from the speaker is clearly audible, ○ (good) if it is audible but not clear, △ (possible) if it is audible and inaudible, almost inaudible or not audible at all When there was not, it was set as x (impossible).

  The speaker used was a USB sound source multimedia speaker (MM-SPL10UBK manufactured by Sanwa Supply Co., Ltd.), and the speaker cover, the speaker cone, and the speaker housing were changed for evaluation. The volume was always constant.

[Example 1]
A sheet having a thickness of 1.0 mm was produced using the composite material D1. In the obtained sheet, the average fiber length of the carbon fiber is 0.25 mm, the standard deviation σ of the fiber length is 0.022 mm, the logarithmic vibration damping factor of the longitudinal and lateral average is 0.170, the loss factor is 0.054, the natural frequency. Was 48.1 Hz. Moreover, the fiber length of the carbon fiber was distributed in a form close to a normal distribution.

  Using the above sheet, a punching material having through holes arranged in a 60 ° staggered pattern having a hole diameter of 2 mm, an aperture ratio of 40%, and a pitch of 3 mm was produced.

  The evaluation speaker cover was evaluated in place of the punching material. As a result, 20 out of 20 panelists were excellent (excellent). In addition, as a result of long-term use in a coastal area near 100 m from the sea, no rust was generated and the through hole was not buried. Furthermore, as shown in FIG. 6, the displacement of the speaker of Example 1 is attenuated earlier than that of Comparative Example 1 described later, and vibration is suppressed early.

[Comparative Example 1]
A sheet having a thickness of 1.0 mm was produced using the metal E1. The obtained sheet had a longitudinal and horizontal average logarithmic vibration damping factor of 0.035, a loss factor of 0.011, and a natural frequency of 71.5 Hz.

  Using the above sheet, a punching material having through holes arranged in a 60 ° staggered pattern having a hole diameter of 2 mm, an aperture ratio of 40%, and a pitch of 3 mm was produced.

  Evaluation was made by replacing the cover of the speaker for evaluation with the punching material made of stainless steel. As a result, 5 out of 20 panelists were Δ (possible) and 15 were × (impossible). Moreover, as a result of long-term use in a coastal area near 100 m from the sea, rust was generated, and 70% or more of the entire through hole was filled with rust. Furthermore, as shown in FIG. 7, the speaker of Comparative Example 1 takes time for the displacement to attenuate, and the vibration suppressing effect is lower than that of Example 1.

[Example 2]
A sheet having a thickness of 0.3 mm was produced using the composite material D2. In the obtained sheet, the average fiber length of the carbon fiber is 0.31 mm, the standard deviation σ of the fiber length is 0.026 mm, the logarithmic vibration damping factor of the longitudinal and transverse average is 0.258, the loss factor is 0.082, the natural frequency. Was 37.1 Hz. Moreover, the fiber length of the carbon fiber was distributed in a form close to a normal distribution.

  The speaker cone for evaluation was evaluated without a speaker cover in place of the speaker cone obtained by heating the sheet at 250 ° C. and vacuum forming. As a result, 20 out of 20 panelists were excellent (excellent). Moreover, as a result of long-term use in a coastal area near 100 m from the sea, the speaker cone was not broken.

[Comparative Example 2]
A sheet having a thickness of 1.0 mm was produced by injection molding using a resin containing 35% glass fiber in the first thermoplastic resin B1. Further, the obtained sheet was cut and thinned to 0.3 mm. In the finally obtained sheet, the logarithmic vibration attenuation factor of the longitudinal and transverse average was 0.069, the loss factor was 0.022, and the natural frequency was 193 Hz.

  An attempt was made to obtain a speaker cone by vacuum forming using the sheet obtained by the injection molding, but it could not be obtained softly. Therefore, a speaker cone having a thickness of 1.0 mm was produced by injection molding.

  In the evaluation speaker, the speaker cone was replaced with the speaker cone obtained by the injection molding, and the evaluation was performed without attaching the speaker cover. As a result, out of 20 panelists, 4 were Δ (possible) and 16 were × (impossible). In addition, as a result of long-term use in a coastal area near 100 m from the sea, no breakage occurred, but a small crack occurred. This small crack is considered to be caused by a weld during injection molding.

[Example 3]
A sheet having a thickness of 0.5 mm was produced using the composite material D3. In the obtained sheet, the average fiber length of the carbon fiber is 0.45 mm, the standard deviation σ of the fiber length is 0.033 mm, the logarithmic vibration damping factor of the longitudinal and transverse average is 0.091, the loss factor is 0.029, and the natural frequency Was 56.2 Hz. Moreover, the fiber length of the carbon fiber was distributed in a form close to a normal distribution.

  Using the sheet, a punching material in which through holes were arranged in a square staggered with a hole diameter of 1.5 mm, an aperture ratio of 70%, and a pitch of 2.25 mm was produced.

  The evaluation speaker cover was evaluated in place of the punching material. As a result, 20 out of 20 panelists were excellent (excellent). In addition, as a result of long-term use in a coastal area near 100 m from the sea, no rust was generated and the through hole was not buried.

[Comparative Example 3]
A 1.0 mm thick sheet made of a resin containing 20% glass fiber in the first thermoplastic resin B2 was produced by injection molding. Further, the obtained sheet was cut and thinned to 0.5 mm. In the finally obtained sheet, the logarithmic vibration damping ratio of the longitudinal and transverse average was 0.041, the loss coefficient was 0.013, and the natural frequency was 145 Hz.

  An attempt was made to produce a punching material in which through holes were arranged in a square staggered pattern having a hole diameter of 1.5 mm, an aperture ratio of 70%, and a pitch of 2.25 mm using the above sheet. The material could not be obtained.

[Example 4]
A sheet having a thickness of 1.5 mm was produced using the composite material D4. In the obtained sheet, the average fiber length of the carbon fiber is 0.2 mm, the standard deviation σ of the fiber length is 0.013 mm, the logarithmic vibration damping factor of the longitudinal and transverse average is 0.078, the loss factor is 0.025, the natural frequency. Was 39.9 Hz. Moreover, the fiber length of the carbon fiber was distributed in a form close to a normal distribution.

  Using the above sheet, a punching material having through holes arranged in a 60 ° staggered pattern having a hole diameter of 1.5 mm, an aperture ratio of 23%, and a pitch of 3.0 mm was produced.

  The evaluation speaker cover was evaluated in place of the punching material. As a result, 20 out of 20 panelists were excellent (excellent). In addition, as a result of long-term use in a coastal area near 100 m from the sea, no rust was generated and the through hole was not buried.

[Comparative Example 4]
A 1.5 mm thick sheet made of a resin containing 15% glass fiber in the first thermoplastic resin B3 was produced by injection molding. In the obtained sheet, the logarithmic vibration attenuation factor of the longitudinal and transverse average was 0.063, the loss factor was 0.020, and the natural frequency was 138 Hz.

  An attempt was made to produce a punching material in which through-holes were arranged in a 60 ° staggered pattern with a hole diameter of 1.5 mm, an aperture ratio of 23%, and a pitch of 3.0 mm, using the above sheet. The material could not be obtained.

[Example 5]
A sheet having a thickness of 1.0 mm was produced using the composite material D5. In the obtained sheet, the average fiber length of the carbon fiber is 0.2 mm, the standard deviation σ of the fiber length is 0.012 mm, the logarithmic vibration attenuation factor of the longitudinal and transverse average is 0.091, the loss factor is 0.029, and the natural frequency is It was 45.2 Hz. Moreover, the fiber length of the carbon fiber was distributed in a form close to a normal distribution.

  Using the above sheet, a punching material having through holes arranged in a 60 ° staggered pattern having a hole diameter of 2.0 mm, an aperture ratio of 30%, and a pitch of 3.5 mm was produced.

  Evaluation was made by replacing the cover of the speaker for evaluation with the punching material of the thermoplastic carbon fiber resin substrate. As a result, 20 out of 20 panelists were excellent (excellent). Further, as a result of long-term use in a coastal area near 100 m from the sea, no rust was generated and no holes were filled.

[Comparative Example 5]
A 1.5 mm thick sheet made of a resin containing 40% glass fiber in the first thermoplastic resin B4 was produced by injection molding. In the obtained sheet, the logarithmic vibration attenuation factor of the longitudinal and transverse average was 0.069, the loss factor was 0.022, and the natural frequency was 192 Hz.

  An attempt was made to produce a punching material in which through holes were arranged with a hole diameter of 2.0 mm, an aperture ratio of 30%, and a pitch of 3.5 mm and a through hole arranged using the above sheet. Couldn't get.

[Example 6]
A sheet having a thickness of 0.8 mm was manufactured using the composite material D6. In the obtained sheet, the average fiber length of the carbon fiber is 0.2 mm, the standard deviation σ of the fiber length is 0.009 mm, the logarithmic vibration damping factor of the longitudinal and transverse average is 0.085, the loss factor is 0.027, and the natural frequency is It was 27.4 Hz. Moreover, the fiber length of the carbon fiber was distributed in a form close to a normal distribution.

  Using the above sheet, a punching material having through holes arranged in a 60 ° staggered pattern having a hole diameter of 1.5 mm, an aperture ratio of 51%, and a pitch of 2.0 mm was produced.

  The evaluation speaker cover was evaluated in place of the punching material. As a result, of 20 panelists, 18 were ◎ (excellent) and 2 were ◯ (good). In addition, as a result of long-term use in a coastal area near 100 m from the sea, no rust was generated and the through hole was not buried.

[Comparative Example 6]
A 1.5 mm-thick sheet made of a resin containing 40% glass fiber in the first thermoplastic resin B5 was produced by injection molding. In the obtained sheet, the logarithmic vibration attenuation factor of the longitudinal and transverse average was 0.060, the loss factor was 0.019, and the natural frequency was 125 Hz.

  An attempt was made to produce a punching material in which through holes were arranged in a 60 ° staggered pattern with a hole diameter of 1.5 mm, an aperture ratio of 51%, and a pitch of 2.0 mm using the above sheet. Couldn't get.

[Example 7]
A sheet having a thickness of 2.0 mm was produced using the composite material D7. In the obtained sheet, the average fiber length of the carbon fibers is 0.3 mm, the standard deviation σ of the fiber length is 0.017 mm, the logarithmic vibration attenuation factor of the longitudinal and transverse average is 0.129, the loss factor is 0.041, and the natural frequency Was 46.5 Hz. Moreover, the fiber length of the carbon fiber was distributed in a form close to a normal distribution.

  The evaluation was made by replacing the bottom surface, both side surfaces, and the top plate of the case W68 × D130 × H160 mm of the speaker for evaluation with the above sheet. As a result, of 20 panelists, 18 were ◎ (excellent) and 2 were ◯ (good). Further, as a result of long-term use in a coastal area near 100 m from the sea, there was no cracking or discoloration.

[Comparative Example 7]
A 2.0 mm thick sheet made of a resin containing 30% glass fiber in the first thermoplastic resin B6 was produced by injection molding. In the obtained sheet, the logarithmic vibration attenuation factor of the longitudinal and transverse averages was 0.015, the loss factor was 0.0047, and the natural frequency was 176 Hz.

  The evaluation was made by replacing the bottom surface, both side surfaces, and the top plate of the case W68 × D130 × H160 mm of the speaker for evaluation with the above sheet. As a result, of 20 panelists, 10 were ◯ (good), 8 were △ (possible), and 2 were x (impossible). In addition, as a result of long-term use in a coastal area near 100 m from the sea, the color changed to yellow although there was no crack.

[Example 8]
A sheet was produced in the same manner as in Example 6.
The speaker cone for evaluation was evaluated without the speaker cover used in Example 1 in place of the speaker cone obtained by heating the sheet to 300 ° C. and vacuum forming. As a result, 19 out of 20 panelists were ◎ (excellent) and one was ○ (good). Further, as a result of long-term use in a coastal area near 100 m from the sea, the speaker cone was not broken.

[Comparative Example 8]
Although it tried to obtain a speaker cone by vacuum forming using the sheet obtained in Comparative Example 6, it could not be obtained softly. Moreover, although it tried to obtain a speaker cone by vacuum forming using the sheet | seat obtained by injection molding in the comparative example 2, it was not able to obtain softly.

  Therefore, in the evaluation speaker used in Example 1, the speaker cone was replaced with the speaker cone obtained by injection molding in Comparative Example 2 and evaluated without attaching a speaker cover. As a result, out of 20 panelists, 2 were ◯ (good), 15 were △ (possible), and 3 were x (impossible).

DESCRIPTION OF SYMBOLS 1 Thermoplastic carbon fiber resin base material 2 Porous sheet 3 Through-hole 4 Speaker cone

Claims (9)

  The speaker is characterized in that it is composed of a thermoplastic carbon fiber resin base material made of a composite material including a thermoplastic resin and carbon fibers, and the logarithmic vibration damping factor of the composite material is 0.07 to 0.30. parts.   The composite material is composed of a thermoplastic carbon fiber resin base material composed of a composite material containing a thermoplastic resin and carbon fibers, the natural frequency of the composite material is 10 Hz to 60 Hz, and the loss factor is 0.025 or more. Speaker parts.   The thermoplastic carbon fiber resin base material contains 5% to 60% by weight of the carbon fiber, and the proportion of carbon fiber having a fiber length of 0.01 mm to 0.5 mm in the total carbon fiber is 60% by weight or more. The speaker component according to claim 1 or 2, wherein:   The thermoplastic carbon fiber resin substrate is a porous sheet having a plurality of through holes, the thickness of the porous sheet is 0.05 mm to 10.0 mm, and the hole diameter of the through holes is 0.1 mm to 100 mm. 4. The speaker component according to claim 1, wherein the total opening area of the through holes is 5% to 75% with respect to the entire sheet surface and is a speaker cover.   The speaker component according to any one of claims 1 to 3, wherein the thermoplastic carbon fiber resin base material has a thickness of 0.05 mm to 2.0 mm, and is a speaker cone.   The speaker component according to any one of claims 1 to 3, wherein the thermoplastic carbon fiber resin base material is a speaker housing having a thickness of 0.1 mm to 10.0 mm.   A method for producing a speaker component according to any one of claims 1 to 6, wherein the thermoplastic carbon is formed from the composite material by melt profile extrusion, melt sheet extrusion, injection molding, vacuum molding or blow molding. A method for producing a speaker component, comprising molding a fiber resin substrate.   When cooling the thermoplastic carbon fiber resin substrate, one surface thereof is brought into contact with a metal shaping surface, and a spring back is provided on a non-contact surface of the thermoplastic carbon fiber resin substrate with the metal shaping surface. The method for manufacturing a speaker component according to claim 7, wherein the speaker component is generated.   A speaker comprising the speaker component according to claim 1.

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