WO2006114980A1

WO2006114980A1 - Diaphragm for speaker, method for producing same, speaker using such diaphragm and apparatus using such speaker

Info

Publication number: WO2006114980A1
Application number: PCT/JP2006/306627
Authority: WO
Inventors: Yoshimichi Kajihara; Masaki Suzumura; Shinya Mizone
Original assignee: Matsushita Electric Industrial Co., Ltd.
Priority date: 2005-04-20
Filing date: 2006-03-30
Publication date: 2006-11-02
Also published as: CN101091413A; CN101091413B; CN2884766Y

Abstract

Disclosed is a diaphragm for speakers containing a resin, an aramid fiber, and an organosilicon compound for binding the resin and the aramid fiber. By having such a constitution, the diaphragm can maintain high elastic modulus and high internal loss which are characteristic to the aramid fibers. Consequently, the diaphragm is increased in the degree of freedom in physical value setting while securing moisture resistance reliability and strength. Such a diaphragm is also excellent in appearance.

Description

Specification

Diaphragm for speaker and manufacturing method thereof, speaker using the diaphragm, and device using the speaker

Technical field

TECHNICAL FIELD [0001] The present invention relates to a speaker diaphragm used in various audio equipment and video equipment, a manufacturing method thereof, and a speaker using the same. Furthermore, the present invention relates to a stereo set using this speaker, a television set, a device such as an automobile.

Background art

FIG. 6 is a cross-sectional view of a diaphragm for a speaker made of resin by conventional injection molding. Diaphragm 16 is made by injection molding using a resin such as polypropylene and heat-melting the resin pellet in a mold whose shape is set in advance. As a resin material used for injection molding, a single material such as polypropylene is generally often used. In addition, there is also a blend type diaphragm 16 formed using different types of resin for the purpose of adjusting the physical property values of the diaphragm 16, that is, adjusting the characteristics and sound quality as a speaker.

[0003] Furthermore, it is difficult to make adjustments using only the resin material. For the physical property values, the reinforcing material such as My Power is mixed and adjusted in the resin material to adjust the characteristics and sound quality of the speaker. Yes. Such a diaphragm is disclosed in, for example, JP-A-2-228197.

[0004] Recently, along with the dramatic improvement in performance of electronic devices such as audio equipment and video equipment, there has been a strong demand from the market to improve the performance of speakers used in these electronic equipment. Therefore, in order to improve the performance of the speaker power, it is essential to improve the performance of the diaphragm that occupies a large weight that determines the sound quality.

[0005] However, conventional diaphragms are manufactured by a papermaking method, a resin injection molding method, or a pressing method. In other words, paper diaphragm vibration resin diaphragms are the mainstream, and each feature is used and divided according to its application while energizing each feature.

[0006] With a paper diaphragm, it is possible to easily mix aramid fibers and My strength by wet-mixing, so that the physical property values can be set finely and the degree of freedom in adjusting speaker characteristics and sound quality is great. There are advantages. However, such a diaphragm is inferior in moisture resistance and water resistance reliability. The paper has the disadvantages unique to paper, and its production requires a great number of processes called papermaking.

[0007] On the other hand, a resin diaphragm obtained by injection molding has excellent moisture resistance, water resistance reliability and dimensional stability, and high productivity. However, even if an inorganic filler such as My Power is used to adjust the physical properties, uniform physical properties cannot be secured. For this reason, the adjustment range of the characteristics and sound quality as a speaker is very narrow.

Disclosure of the invention

[0008] The present invention provides a speaker diaphragm capable of ensuring moisture resistance, water resistance reliability and dimensional stability with a large degree of freedom in adjusting the characteristics and sound quality as a speaker, having an excellent appearance, and improving productivity. It is. The speaker diaphragm of the present invention contains a resin, an aramid fiber, and an organosilicon compound that binds the resin and the polyamide fiber. This configuration retains the high elastic modulus and high internal loss that are the characteristics of aramid fibers, increasing the degree of freedom in setting the physical properties of the diaphragm, ensuring moisture resistance reliability and strength, and excellent appearance. A diaphragm can be obtained. Brief Description of Drawings

FIG. 1A is a cross-sectional view of a speaker diaphragm in an embodiment of the present invention.

FIG. 1B is a conceptual enlarged cross-sectional view of the diaphragm shown in FIG. 1A.

FIG. 2 is a plan view of the diaphragm shown in FIG. 1A.

FIG. 3 is a cross-sectional view of the speaker in the embodiment of the present invention.

FIG. 4 is an external view of a minicomponent system in an embodiment of the present invention.

FIG. 5 is a sectional view of the automobile in the embodiment of the present invention.

FIG. 6 is a cross-sectional view of a conventional speaker diaphragm.

Explanation of symbols

[0010] 1 Diaphragm

1A oil

1B aramid fiber

1C organosilicon compound

2 Magnet

3 Top plate 5 Magnetic circuit

6 Magnetic gap

7 frames

8 Voice coil

9 edge

10 Speaker

11 Enclosure

12 amplifiers

13 Operation unit

14 Mini component system

15 cars

16 ¾ moving plate

21 Speaker system

51 Rear tray

52 Front panel

53 Drive unit

54 Steering

55 Boai

56 Front wheel

57 Rear wheel

58 seats

BEST MODE FOR CARRYING OUT THE INVENTION

FIG. 1A is a sectional view of a speaker diaphragm according to an embodiment of the present invention, and FIG. 1B is an enlarged sectional view of the same concept. Fig. 2 is a plan view of the same. Diaphragm 1 is configured by injection molding a material in which resin 1A is mixed with aramid fiber 1B, and resin 1A and aramid fiber 1B are firmly bonded with organic silicon compound 1C. That is, diaphragm 1 includes resin 1A, aramid fiber 1B, and organosilicon compound 1C that binds resin 1A and aramid fiber 1B. Mu

[0012] By incorporating the organosilicon compound 1C, the binding force between the resin 1A and the aramid fiber IB is increased, and the adhesion between the two is improved. As a result, energy loss in the diaphragm 1 is reduced, and the characteristics of the aramid fiber 1B are utilized more effectively, and a diaphragm having high strength and high elastic modulus can be obtained. In particular, when the resin 1A and the aramide fiber 1B are combined by the organosilicon compound 1C, the adhesion between the two is further improved.

[0013] Crystalline or amorphous olefin fin resin is preferably used as the resin 1A. Formability is improved by using olefin resin. In addition, by using and separating crystalline resinous material and amorphous resin material according to the application, it is possible to satisfy the optimum physical property values as the resinous material.

[0014] As the organosilicon compound 1C, a so-called aminosilane coupling agent or a hydrolyzable long-chain alkylsilane having 6 or more carbon atoms can be used. Among these, it is preferable to use an organosilicon compound having an amino group. By mixing such an organosilicon compound 1C, the resin 1A and the aramide fiber 1B are more firmly bound. As a result, the physical properties of the aramid fiber 1B function effectively, and the diaphragm 1 having a higher elastic modulus can be obtained. Note that 3-aminopropyltriethoxysilane, N-2 (aminoethinole) 3-aminopropyltriethoxysilane, and 3-aminopropyltrimethoxysilane are more effective as the organosilicon compound 1C having an amino group used here. It is. As the hydrolyzable long-chain alkylsilane, hexyltrimethoxysilane or decyltrimethoxysilane can be used.

[0015] Hereinafter, a specific example in which polypropylene is used for the resin 1A will be described. First, 90wt% polypropylene and 10wt% aramid fiber with a fiber length of 3mm are granulated and kneaded. At this time, 1.5 parts by weight of 3-aminopropyltriethoxysilane as an organosilicon compound 1C is mixed in 100 parts by weight of the kneaded product. The organosilicon compound 1C may be added before kneading the resin 1A and the aramide fiber 1B, or may be added during kneading.

[0016] At this time, the heat granulation is preferable because polypropylene and aramid fiber 1B, which are the resin 1A, are combined, and the familiarity of the resin 1A and the aramid fiber 1B is improved and uniformly dispersed.

[0017] Pellets are prepared from the kneaded material thus prepared, and the pellets are injection-molded and shaken. Mold moving plate 1. In this way, the diaphragm 1 of sample F is manufactured. Then, after measuring the specific gravity of diaphragm 1, a sample of 32mm x 5mm, which is a part of it, is extracted and the elastic modulus and internal loss are measured. The characteristics of conventional paper or resin, and vibration plates (samples A to E) containing 10 wt% of reinforcing material are measured in the same way, and the results are shown in (Table 1). Internal loss is one of the indices that express the characteristics of the material used for the diaphragm, and represents the ability to dissipate the energy to the outside when kinetic energy such as vibration is applied from the outside. The higher the internal loss, the lower the unnecessary reverberation and the better the sound quality.

[0018] [Table 1]

As is clear from (Table 1), the specific gravity of the material of diaphragm 1 of sample F according to the present embodiment is smaller than that of sample E using My force as the reinforcing material. In addition, it has a high elastic modulus and high internal loss compared to samples D and E, which are sample papers A to C, which are conventional paper diaphragms, and is extremely effective in terms of physical properties.

[0020] Polypropylene is generally easily available and injection molding is easy, but the present invention is not limited to this. Depending on the specified characteristic value, other types of resin can be used and used freely. For example, when high heat resistance and high solvent resistance are required, it is possible to use an engineering plastic that matches the application.

[0021] Note that the diaphragm 1 using the aramid fiber 1B can reproduce a bright timbre with a clear sense, and can suppress dark and uniform timbre peculiar to fat.

[0022] Further, when it is desired to adjust the sound quality by reinforcing the diaphragm 1, adding some accents to the sound, or giving a peak to the sound pressure frequency characteristics, a reinforcing material may be mixed. As such a strong reinforcing material, My strength, graphite, talc and cellulose fiber can be used. The elastic modulus can be increased by mixing My Strength into the reinforcing material. If you add Graphite, Increases efficiency and internal loss. Inclusion of talc can increase internal loss. By mixing the cellulose fiber, the internal loss can be increased without entanglement of the cellulose fiber and the aramid fiber without lowering the porosity. Further, a tough fiber such as carbon fiber may be used as the fiber. When carbon fiber is mixed, rigidity increases and elastic modulus improves. In addition, by combining these materials, the physical property values of the diaphragm 1 can be freely adjusted with high accuracy, and predetermined characteristics and sound quality can be realized.

[0023] A fluidity modifier may also be mixed. As such a modifying material, for example, a flowable powdered calcium stearate can be used. In particular, use of a fatty acid having an amino group is preferred because a thin and light diaphragm 1 highly filled with aramid fiber 1B can be obtained by injection molding. As the fatty acid having such an amino group, stearic acid amide or oleic acid amide can be used.

[0024] Table 2 shows the results of comparing the fluidity (Ml) when stearic acid amide is mixed as a fluidity modifier and when it is not mixed. Evaluation is being carried out in accordance with IS K7210

[0025] [Table 2]

[0026] From (Table 2), when the fluidity modifier is mixed, the fluidity in the molten state is clearly improved as compared with the case where the fluidity modifier is not mixed. Therefore, it is possible to obtain the diaphragm 1 having a large degree of freedom of shape by injection molding even when the aramid fiber 1B is highly filled. Further, when the filling amount of the aramid fiber 1B is the same, it is possible to obtain a thinner diaphragm 1 by injection molding if a fluidity modifier is mixed.

[0027] Regarding the realization of this predetermined characteristic and sound quality, deep know-how regarding characteristic making and sound making The force that requires how-to is generally carried out by the following method. In other words, the speaker characteristics and sound can be modified to some extent by changing the parameters of the components, and the characteristics and sound quality can be approached.

[0028] For example, a case is assumed in which the parameters of the components other than the diaphragm 1 among the components of the speaker are fixed. The parameters that can be changed in the diaphragm 1 are area, shape, weight, surface thickness, etc., other than the physical property values. However, the area, shape, weight, and surface thickness of diaphragm 1 are almost determined at the initial stage of speaker design. That is, the sound pressure frequency characteristic and sound quality of the speaker are roughly determined by conditions other than the physical property value of diaphragm 1.

[0029] In this case, unnecessary peaks and dips occur in the sound pressure frequency characteristics, and distortion often occurs greatly in a specific frequency band. As for sound quality, the sound quality depends greatly on the sound pressure frequency characteristics. These causes are due to the area, shape, weight, and surface thickness of diaphragm 1, and in particular, are often due to the vibration mode of diaphragm 1. In order to improve such unnecessary peaks, dips and distortion, and to obtain good sound quality, diaphragm materials can be selected according to the following procedure.

[0030] First, a material that can satisfy the sound pressure frequency characteristics, sound quality, and reliability grade required for the speaker is selected as resin 1A, aramid fiber IB, and other mixed materials. In this case, the base resin 1A is selected with a particular emphasis on reliability such as its heat-resistant grade, and a material whose specific tone is close to the specified tone is selected.

[0031] Then, each material is selected for an unnecessary peak or dip in the sound pressure frequency characteristic to be deleted. For countermeasures against dip, select a resin material that has resonance at that frequency. Conversely, when countermeasures against peaking, select a material that has internal loss at that frequency. For this material selection, the density, elastic modulus, internal loss, timbre, resonance frequency when molded into the shape of diaphragm 1, etc. are taken into account for resin 1A, aramid fiber 1B, and other mixed materials. Select while.

[0032] Then, the selected materials are kneaded to produce a master batch pellet highly filled with aramid fiber 1B for injection molding. Next, this master batch pellet is melted and shot. Diaphragm 1 is obtained by extrusion molding.

[0033] The physical property values and the like of the diaphragm 1 obtained in this way are measured and evaluated. In addition, the speaker 1 is prototyped using the diaphragm 1, the characteristics and sound quality are actually measured, and the final audition is performed. If the evaluation does not provide the desired characteristics and sound quality, repeat this prototype process many times. In the process, we will improve the selection of materials and their blending ratio, and gradually bring them closer to the target characteristics and sound quality.

[0034] By repeating the above-described process, it is possible to finish the diaphragm 1 that is capable of satisfying predetermined characteristics and sound quality, or is very close.

[0035] The length of the aramid fiber 1B is preferably 0.3 mm or more and 6 mm or less. By using the aramid fiber 1B in this length range, the effect when combined with the resin 1A and heat granulation is efficiently exhibited, and the productivity and quality are improved. The fiber length of the aramid fiber 1B is not necessarily adjusted to be the same. For example, a short fiber having a fiber length of 0.3 mm or more and less than lmm may be combined with a long fiber having a fiber length of 1 mm or more and 6 mm or less. In this way, by using the aramid fiber 1B in which long fibers and short fibers are combined, resonance can be relieved and fine sound quality adjustment can be performed.

[0036] If the fiber length of the aramid fiber 1B is shorter than 0.3 mm, the effect of the aramid fiber 1B cannot be obtained efficiently and a high elastic modulus cannot be expected. On the other hand, when the length is longer than 6 mm, poor dispersion tends to occur due to secondary aggregation resulting from entanglement between the polyamide fibers 1B. For this reason, it takes a long time to knead the resin 1A. Alternatively, agglomerates of aramid fiber 1B appear on the surface of diaphragm 1 and the appearance is impaired. Thus, productivity and quality are reduced.

[0037] Preferably, it is composited with an aramid fiber of 3 mm or less. If the fiber length is longer than this, it will be difficult to form the diaphragm 1 thinly.

[0038] Further, the mixing ratio of the aramid fiber 1B to the resin 1A is preferably 5% or more and 50% or less. By setting the blending ratio in this range, the effect when kneaded with rosin 1A is efficiently exhibited, and the productivity and quality are improved.

[0039] When the mixing ratio of the aramid fiber 1B is less than 5%, the effect of the aramid fiber 1B hardly appears. On the other hand, if it is more than 50%, it takes a long time to knead with the resin 1A. Also, since injection molding becomes difficult, productivity and dimensional stability are reduced, and the degree of freedom in shape is small. Become.

[0040] As described above, by configuring the diaphragm 1 by injection molding the material in which the resin 1A and the aramide fiber IB are mixed, the degree of freedom in setting the physical properties of the diaphragm 1 is increased. That is, vibration plate 1 having high elastic modulus and high internal loss, which are the characteristics of aramid fiber 1B, and excellent in moisture resistance reliability and appearance can be obtained. By producing such a diaphragm 1 by injection molding, productivity and dimensional stability are also improved.

[0041] In general, the fusion of the resin 1A and the aramid fiber 1B is generally very difficult to laminate, and then a diaphragm is formed by hot pressing. However, the diaphragm 1 can be reduced in thickness and durability can be secured by binding both of them together with the organosilicon compound 1C. As a result, the vibration plate 1 can be molded by injection molding, which improves productivity.

[0042] In the present embodiment, injection molding is applied! /, But is not limited to this. For example, the diaphragm 1 may be formed by pressing a sheet made by a solution casting method using a material such as PP resin aramide fiber with a die with vertical force. If the vibration plate 1 is thin while being pressed, it is preferable to apply injection molding to cause distortion. By using the organosilicon compound 1C as described above, the thickness can be made 0.2 mm or more and 0.5 mm or less, more preferably 0.2 mm or more and 0.3 mm or less even by injection molding. Thus, by obtaining the thin diaphragm 1, a speaker having excellent sound pressure characteristics can be provided.

Next, the speaker 10 using the diaphragm 1 will be described. FIG. 3 is a cross-sectional view of the speaker in the present embodiment. In the speaker 10, an inner magnet type magnetic circuit 5 is configured by sandwiching a magnet 2 in which an upper plate 3 and a yoke 4 are magnetized. The frame 7 is coupled to the yoke 4 of the magnetic circuit 5. The periphery of the diaphragm 1 is bonded (adhered) to the peripheral edge of the frame 7 via an edge 9. Further, one end of the voice coil 8 is coupled to the central portion of the diaphragm 1, and the opposite end of the voice coil 8 is coupled so as to fit into the magnetic gear 6 of the magnetic circuit 5. That is, the voice coil 8 is coupled to the diaphragm 1 and is disposed within a range of action of magnetic flux generated from the magnetic circuit 5.

With this configuration, the speaker 10 having a high elastic modulus and a high internal loss, which is a feature of the aramid fiber 1B, which has a large degree of freedom in adjusting characteristics and sound quality, can be obtained. The speaker 10 can ensure moisture resistance reliability and strength, has an excellent appearance, and has high productivity. In the above description, the speaker 10 having the inner magnet type magnetic circuit 5 has been described. However, the present invention is not limited to this, and the present invention may be applied to a speaker having an outer magnet type magnetic circuit.

Next, an example of a device using the speaker 10 configured as described above will be described. FIG. 4 is an external view of an audio minicomponent system that is an electronic device according to the present embodiment.

The speaker 10 is incorporated in an enclosure 11 to constitute a speaker system 21. The amplifier 12 includes an amplification circuit for an electric signal input to the speaker system 21. An operation unit 13 such as a player outputs a source input to the amplifier 12. As described above, the audio mini-component system 14 that is an electronic device includes the amplifier 12, the operation unit 13, and the speaker system 21. The amplifier 12, the operation unit 13, and the enclosure 11 are the main parts of the mini component system 14. That is, the speaker 10 is attached to the main body of the mini component system 14. The voice coil 8 of the speaker 10 is supplied with power from the amplifier 12 of the main body and emits sound from the diaphragm 1. This configuration provides a mini component system 14 that enables highly accurate characteristics, sounds, and designs that could not be realized in the past.

[0048] Although the audio mini-component system 14 has been described as an application of the speaker 10 to a device, the present invention is not limited to this. It can also be applied to portable portable audio devices and their charging systems. Furthermore, it can be widely applied and deployed in video equipment such as liquid crystal televisions and plasma display televisions, information communication equipment such as mobile phones, and electronic equipment such as computer-related equipment.

Next, an example of another device to which the speaker 10 is applied will be described. FIG. 5 is a cross-sectional view of an automobile 15 which is a device (device) in the embodiment of the present invention.

The automobile 15 includes a body 55, a seat 58, a drive unit 53, a steering 54, a front wheel 56, and a rear wheel 57. The seat 58 and the steering 54 are installed in a vehicle compartment provided in the body 55, and the drive unit 53 is installed in a machine compartment provided in the body 55. The steering 54 operates a front wheel 56 that is a steering wheel. The drive unit 53 includes an engine and a motor, and drives a rear wheel 57 that is a drive wheel. The driving unit 53 may drive the front wheels 56. The front wheel 56 and the rear wheel 57 support the body 55. The rear tray 51 provided inside the body 55 of the automobile 50 incorporates the speaker 10 and is used as a part of the car audio. this In the configuration, the speaker 10 is mounted on the automobile 15 that is the main body, and the voice coil 8 of the speaker 10 is supplied with power from the automobile 15 that is the main body and emits sound from the diaphragm 1.

[0051] With this configuration, it is possible to create highly accurate characteristics that make the most of the features of the aramid fiber 1B of the speaker 10, and to create and design sound. Therefore, it is possible to improve the degree of freedom in acoustic design of a device (device) such as an automobile 15 equipped with the speaker 10.

Note that the speaker 10 may be incorporated in the front panel 52 and used as a part of car navigation or audio.

Industrial applicability

[0053] The speaker diaphragm according to the present invention and the speaker using the diaphragm can be applied to electronic devices such as audiovisual equipment and information communication equipment that require high-precision characteristics and sound creation, and further to devices such as automobiles. .

Claims

The scope of the claims

[I] resin,

Aramid fiber,

An organosilicon compound that binds the resin and the aramid fiber,

A diaphragm for speakers.

[2] The thickness is 0.2 mm or more and 0.5 mm or less,

2. The speaker diaphragm according to claim 1.

[3] The resin and the aramid fiber are combined! /

2. The speaker diaphragm according to claim 1.

[4] The resin is a crystalline olefin fin resin,

2. The speaker diaphragm according to claim 1.

[5] The resin is an amorphous olefin resin.

2. The speaker diaphragm according to claim 1.

[6] The resin is polypropylene.

2. The speaker diaphragm according to claim 1.

[7] The resin is an engineering plastic.

2. The speaker diaphragm according to claim 1.

[8] further comprising a reinforcement,

2. The speaker diaphragm according to claim 1.

[9] The reinforcing material is composed of at least one of my strength, graphite, talc, and cellulose fiber.

9. The speaker diaphragm according to claim 8.

[10] further comprising a fluidity modifier,

2. The speaker diaphragm according to claim 1.

[II] The fluidity modifier is a fatty acid having an amino group,

11. The speaker diaphragm according to claim 10.

[12] The organosilicon compound has an amino group.

2. The speaker diaphragm according to claim 1.

[13] The fiber length of the aramid fiber is 0.3 mm or more and 6 mm or less.

2. The speaker diaphragm according to claim 1.

[14] The fiber length of the aramid fiber is 3 mm or less,

The speaker diaphragm according to claim 13.

[15] The mixing ratio of the aramid fiber to the resin is 5% or more and 50% or less.

2. The speaker diaphragm according to claim 1.

[16] Magnetic circuit,

A frame coupled to the magnetic circuit;

A diaphragm that includes a resin, an aramid fiber, an organic silicon compound that binds the resin and the aramid fiber, and is coupled to a peripheral edge of the frame;

A voice coil coupled to the diaphragm and disposed within a range of action of magnetic flux generated from the magnetic circuit,

Speaker.

[17] The main body,

A magnetic circuit;

A frame coupled to the magnetic circuit;

A diaphragm that includes a resin, an aramid fiber, and an organosilicon compound that binds the resin and the aramid fiber, and is coupled to a peripheral portion of the frame;

A voice coil coupled to the diaphragm and disposed within an action range of the magnetic flux generated by the magnetic circuit force, and provided with a speaker that is fed with the main body force.

machine.

18. The device according to claim 17, wherein the main body includes a circuit that amplifies at least an input signal to the speaker.

[19] The body portion is operated by a body, a drive portion provided in the body, a drive wheel that is driven by the drive portion and supports the body, a steering wheel provided in the body, and the steering. Steering wheel to be

The speaker is provided inside the body, The device of claim 17.

[20] A) preparing a kneaded product of a resin, an aramid fiber, and an organosilicon compound for binding the resin and the aramid fiber;

B) forming the kneaded product,

Manufacturing method of speaker diaphragm.

[21] The kneaded material is injection-molded in the B step.

21. A method for manufacturing a speaker diaphragm according to claim 20.

[22] The kneaded material is combined by heat granulation in the A step,

21. A method for manufacturing a speaker diaphragm according to claim 20.