JP2008131203A - Speaker system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a speaker system capable of mainly increasing a degree of freedom of design of acoustic characteristics. <P>SOLUTION: The speaker system includes a vibration body having a diaphragm, a drive cone, and first and second edges, and a frame supporting the vibration body. Spaces are formed between respective elements of the vibration body. Air in the spaces functions as an air spring elastically supporting the vibration body. The frame has an opening portion which communicates with the spaces and the outside space and varies the equivalent compliance of the air spring present in the spaces. The equivalent compliance is varied by varying the size of the opening portion. Consequently, the capacity of the spaces can substantially be varied by suitably varying the size of the opening portion. The equivalent compliance can, therefore, be varied and the elastic force of the air spring present in the spaces can be varied. Consequently, acoustic characteristics can easily be varied to increase the degree of freedom of design of the acoustic characteristics. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to the structure of a speaker device with variable acoustic characteristics.

  Conventionally, a vibrator having a voice coil, a voice coil bobbin that winds the voice coil, a damper that elastically supports the voice coil bobbin, and a diaphragm supported by the voice coil bobbin, a magnetic circuit, and a vibrator And a frame that supports a magnetic circuit (also referred to as a “damper-supported speaker device”) are known.

  As this type of speaker device, for example, by providing a vent hole in the side surface portion of the frame, air existing in the space between the back surface of the diaphragm located on the opposite side to the acoustic radiation side and the magnetic circuit is removed. A speaker device configured to escape to the outside is known (see, for example, Patent Document 1). As described above, by providing the air hole in the side surface of the frame, it is possible to prevent the air pressure in the space between the back surface of the diaphragm and the magnetic circuit from increasing. As a result, it is said that the diaphragm can be prevented from vibrating due to the air pressure, the diaphragm can be vibrated for a long time, and the sensitivity of the speaker device can be improved.

  In addition, there is known a speaker device including a speaker device diaphragm configured to provide a plurality of slits radially with respect to a roll-shaped edge joined to the outer peripheral portion of the diaphragm (for example, , See Patent Document 2). Thus, by providing a plurality of slits radially with respect to the edge, the expansion and contraction motion of the edge can be absorbed, and the force-dimensional displacement distortion (linearity) curve exerted on the speaker device diaphragm is improved. In particular, when the diaphragm is vibrated with a large amplitude, the harmonic distortion seen in the low frequency band can be significantly reduced.

  In other words, in order to improve the sound quality, a function that expresses the relationship between the force acting on the edge and the magnitude of displacement when the edge is extended by receiving the force (the force acting on the edge is expressed as the X axis). , Taking the magnitude of the edge displacement on the Y axis, the origin represents when the edge is stationary, the force acting on the edge at that time, and the edge displacement is zero). It is desirable that the inclination is constant.

  For example, FIG. 10 shows a curve G1 that is constant from the origin O to the displacement B ′ point and a constant slope from the origin O to the A ′ point in the (force acting on the edge) − (displacement of the edge)} curve. However, there are two types of curves G2 in which the slope is not constant from the point A ′ to the point B ′, and tends to fall to the right. Hereinafter, the former curve G1 is referred to as “high linearity characteristics”, and the latter curve G2 is referred to as “low linearity characteristics”.

  By the way, in the edge described in Patent Document 2, the linearity characteristic is high due to the above-described action.

  Patent Document 3 describes a speaker device for low-pitched sound reproduction that can maintain the displacement of the vibrating body of the speaker unit at the center position of the speaker unit without providing an intake / exhaust pump, a control power amplifier, or the like. Has been.

  The speaker device for bass reproduction described in Patent Document 3 includes a speaker unit, a cabinet that accommodates the speaker unit, and means for imparting negative stiffness to the vibration system. By detecting the displacement and returning the detection signal to the power amplifier for reproducing the source signal that drives the speaker unit by the feedback circuit, it is maintained that the vibrating body of the speaker unit is displaced at the center position of the speaker unit. The

  Further, in Patent Document 4, it is possible to prevent dust from entering the inside of the speaker device by forming at least one small hole in the frame on the rear side in the sound emission direction from the mounting position of the damper. Possible speaker devices are described.

JP 2002-171596 A Japanese Unexamined Patent Publication No. 7-23497 JP 2001-157290 A JP 2005-318339 A

By the way, recently, an in-vehicle audio system that incorporates a speaker device for reproducing heavy bass such as a woofer or a subwoofer is increasing.

  In the case of such an in-vehicle speaker device, it is important to make the speaker device thin so that the speaker device can be incorporated even in a portion where the depth dimension is limited in the door or ceiling panel of the vehicle. Yes.

  However, in the conventional speaker apparatus in which the voice coil bobbin is elastically supported by the damper as described above, a space for arranging the damper must be secured between the diaphragm and the magnetic circuit, and the space for installing the damper is required. Therefore, it is difficult to reduce the size of the speaker device in the axial direction, which has been a bottleneck in reducing the thickness and size of the speaker device.

  In addition, since the damper usually has a higher stiffness than the edge, mechanical fatigue due to long-term use occurs earlier than the edge, which may cause a failure of the speaker device such that the diaphragm cannot be sufficiently supported. It was.

  Also, in a damper-supported speaker device, the stiffness (= 1 / compliance) of the speaker device is expressed as the sum of the damper and the stiffness of the edge of the diaphragm itself, and these stiffnesses are the materials constituting the damper and the edge. Therefore, the degree of freedom in designing the acoustic characteristics is small.

  Further, in the speaker devices described in Patent Documents 1 and 2, the sound quality is improved by providing a vent on the side surface of the frame or by providing a plurality of slits radially on the edge. However, such vents and slits are only manufactured at the manufacturer's manufacturing stage, and the size of the vents and slits can be changed later on the end user side to obtain the desired It cannot be adjusted to obtain the acoustic characteristics.

  Examples of problems to be solved by the present invention include the above. The present invention enables a speaker device to freely change acoustic characteristics by changing air resistance, to increase the degree of design freedom of acoustic characteristics, and to subsequently change acoustic characteristics freely. For example, it is possible to make it possible to make the speaker device thinner and smaller, to improve the deterioration of the function of supporting the diaphragm due to mechanical fatigue of the damper caused by long-term use. It is done.

  The invention according to claim 1 is a speaker device including a vibrating body and a support body that supports the vibrating body, and a space is formed between the vibrating body and the support body, The air present in the space has a function of an air spring that elastically supports the vibrating body, and at least one of the members constituting the vibrating body and the support body includes the space and the external space. And an opening for varying the compliance of the air spring in the space.

  In one embodiment of the present invention, the speaker device includes a vibrating body and a support body that supports the vibrating body, and a space is formed between the vibrating body and the support body. The air present in the air has a function of an air spring that elastically supports the vibrating body, and at least one of the members constituting the vibrating body and the support body communicates with the space and the external space. In addition, an opening for varying the compliance existing in the air spring in the space is provided.

  The speaker device includes a vibrating body and a support body that supports the vibrating body. A space is formed between the vibrating body and the support. The air existing in the space has a function of an air spring that elastically supports the vibrating body. As a result, there is no need to provide a damper, which can contribute to the reduction in size and thickness of the speaker device.

  In this speaker device, in particular, at least one member constituting the vibrating body and the support body communicates with a space and an external space (a space outside the speaker device) and is an air spring that exists in the space. An opening for varying the compliance is provided. In a preferred example, the compliance of the air spring existing in the space can be varied by changing the size (area) of the opening.

  Therefore, in this speaker device, the size of the volume of the space can be substantially changed by appropriately changing the size (area) of the opening according to the specifications. Thereby, since the compliance of the air spring which exists in the said space can be changed, the elastic force of the air spring which exists in the said space can be changed. As a result, the acoustic characteristic can be easily changed to a desired characteristic, and the degree of freedom in designing the acoustic characteristic can be improved.

  In a preferred example, the vibration body includes a vibration plate and an edge that elastically supports the vibration plate, and the opening portion is a member of the vibration plate, the edge, and the member constituting the support body. It is preferable that at least one member is provided.

  In one aspect of the above speaker device, the support body is disposed so as to surround the vibration body, and the vibration body is elastic by a voice coil, a voice coil bobbin around which the voice coil is wound, and the support body. A diaphragm that is supported by the motor, a drive cone that transmits the vibration of the voice coil to the diaphragm, a first edge that elastically supports the drive cone, and a second that elastically supports the diaphragm. And an edge. As a result, there is no need to provide a damper, which can contribute to the reduction in size and thickness of the speaker device. In this aspect, the drive cone attached coaxially to the diaphragm can be formed of the same material as the diaphragm, and mechanical fatigue is less likely to occur compared to a damper. It is possible to prevent the deterioration of the acoustic characteristics due to the noise and to extend the life of the speaker device. In this aspect, the space is formed between the drive cone, the diaphragm, the first edge, the second edge, and the support, and the opening is It is preferable that the drive cone, the diaphragm, the first edge, the second edge, and the member constituting the support are provided on at least one member.

  In another aspect of the above speaker device, an acoustic resistance member is attached to the opening. Here, as an acoustic resistance member, the fiber material etc. which are comprised from well-known fibers, such as glass wool and a nonwoven fabric, etc. are mentioned, for example.

  Thus, after the speaker device is manufactured, the amount of the acoustic resistance member to be inserted into the opening portion, the material, dimensions, and shape of the acoustic resistance member to be inserted into the opening portion are changed afterwards, or the holes and the like are changed. It is possible to change the aperture ratio of the acoustic resistance member by providing a large number of such holes. Therefore, since the compliance of the air spring existing in the space can be easily changed, the elastic force of the air spring existing in the space can be easily changed. As a result, the acoustic characteristics can be changed to desired characteristics afterwards.

  In another aspect of the speaker device, the support includes a cylindrical cylindrical portion having the opening, and an acoustic resistance member is provided in the opening. Here, as an acoustic resistance member, the fiber material etc. which are comprised from well-known fibers, such as glass wool and a nonwoven fabric, etc. are mentioned, for example. In this aspect, after the speaker device is manufactured, the amount of the acoustic resistance member to be inserted into the opening of the cylindrical portion afterwards, the material, dimensions, and shape of the acoustic resistance member to be inserted into the opening are changed, holes, etc. Can be formed on the acoustic resistance member, or a large number of such holes can be provided to change the aperture ratio of the acoustic resistance member. Thereby, since the compliance of the air spring which exists in the said space can be changed easily, the elastic force of the air spring which exists in the said space can be changed easily. As a result, the acoustic characteristics can be changed to desired characteristics afterwards.

  In another aspect of the speaker device, an opening variable mechanism for changing the size of the opening is provided at a position corresponding to the opening. This makes it easy to change the size (area) of the opening through an opening variable mechanism after manufacturing the speaker device. Therefore, since the compliance of the air spring existing in the space can be easily changed, the elastic force of the air spring existing in the space can be easily changed. As a result, the acoustic characteristics can be changed to desired characteristics afterwards.

  In another aspect of the speaker device, the opening variable mechanism includes a closing member for closing the opening, a slide mechanism capable of moving the closing member in the opening / closing direction of the opening, Have As a result, according to the specifications of the speaker device, the opening can be closed completely or a predetermined ratio by sliding the closing member toward the opening. On the contrary, by sliding the closing member in a state where the opening is closed to the slide mechanism side, the opening can be fully opened or opened at a predetermined rate. Therefore, after the speaker device is manufactured, the size (area) of the opening can be easily changed later through the opening variable mechanism. Thereby, since the compliance of the air spring which exists in the said space can be changed easily, the elastic force of the air spring which exists in the said space can be changed easily. As a result, the acoustic characteristics can be changed to desired characteristics afterwards.

  In another aspect of the speaker device, the opening is closed by a lid having at least one hole, and the lid is opened and closed by moving the closing member in the opening and closing direction of the opening. Is done. Thus, after the speaker device is manufactured, the size (area) of the opening is indirectly changed by changing the size (area) of closing the lid by the closing member of the opening variable mechanism. Can be changed. Therefore, since the compliance of the air spring existing in the space can be easily changed, the elastic force of the air spring existing in the space can be easily changed. As a result, the acoustic characteristics can be changed to desired characteristics afterwards.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

[Configuration of speaker device]
First, the configuration of the speaker device 100 according to the embodiment of the present invention will be described with reference to FIGS.

  FIG. 1 is a cross-sectional view of a speaker device 100 according to an embodiment of the present invention cut at a position passing through the central axis L1. Fig.2 (a) shows sectional drawing which cut | disconnected the drive cone 7 based on a present Example in the position which passes along the central axis L1. FIG. 2B is a cross-sectional view of the diaphragm 8 according to the present embodiment cut at a position passing through the central axis L1.

  The speaker device 100 mainly includes an outer magnetic type magnetic circuit 30 having a yoke 1, a plurality of magnets 2, a plate 3, and an annular member 4, a voice coil bobbin 5, a voice coil 6, and a drive cone 7. And a vibration body 31 having a diaphragm 8, a first edge 9, a second edge 10, and a cap 11, a frame (support body) 12, and other components. Here, the other components include a gasket 13 and a speaker terminal 17. In the present invention, the shape and driving method of the speaker device 100 are not limited.

(Configuration of magnetic circuit)
The configuration of the magnetic circuit 30 is as follows.

  The yoke 1 has a columnar center pole 1a and a flange portion 1b provided so as to extend outward from the lower end of the outer peripheral surface of the center pole 1a. The center pole 1a is provided with a through hole 1h penetrating in the acoustic radiation direction Y1. The through-hole 1h communicates with the external space S2, and is mainly used for the air pressure in the space formed on the back side of the cap 11 that is located on the opposite side to the acoustic radiation direction Y1 when the vibrating body 31 vibrates. It has a role to prevent change. One of the plurality of magnets 2 has an annular shape and is mounted on the flange portion 1 b of the yoke 1. Of the plurality of magnets 2, the other magnet 2 has an annular shape and is mounted on the one magnet 2. The annular member 4 has a shape obtained by combining a cylindrical cylindrical portion and an annular portion having a substantially annular shape. The annular member 4 is disposed on the plate 3 in a state where the cylindrical portion is inserted into the gap between the plate 3 and the center pole 1a. Between the annular member 4 and the center pole 1a, a magnetic gap 32 in which the magnetic fluxes of the plurality of magnets 2 are concentrated is formed.

(Structure of vibrating body)
The vibrating body 31 has a voice coil bobbin 5, a voice coil 6, a drive cone 7, a diaphragm 8, a first edge 9, a second edge 10 and a cap 11 as constituent members. It is as follows.

  The voice coil bobbin 5 has a cylindrical shape and is disposed so as to surround the upper end portion of the outer peripheral surface of the center pole 1a.

  The voice coil 6 is wound around the lower end portion of the outer peripheral surface of the voice coil bobbin 5 and is located in the magnetic gap 32. The voice coil 6 has a pair of plus / minus lead wires (not shown). The positive lead wire is an input wiring for an L (or R) channel signal, and the negative lead wire is an input wiring for a ground (GND) signal. The pair of plus / minus lead wires are electrically connected to a speaker terminal 17 attached to the frame 12. The speaker terminal 17 is also electrically connected to a pair of output wirings on the amplifier side.

  As shown in FIG. 2A, the drive cone 7 has a substantially annular shape and an uneven cross-sectional shape, a first support portion 7ca that supports an inner peripheral portion of a diaphragm 8 described later, and a vibration 2nd support part 7da which supports the center part of the board 8 is provided. The first support portion 7ca is provided outside and above the inner peripheral portion 7a of the drive cone 7. The second support portion 7 da is provided outside and above the first support portion 7 ca in the drive cone 7, and is provided inside the outer peripheral portion 7 b of the drive cone 7. As shown in FIG. 1, the drive cone 7 is attached to the upper end portion of the outer peripheral surface of the voice coil bobbin 5. The drive cone 7 has a role of transmitting the vibration of the voice coil 6 to the diaphragm 8 via the voice coil bobbin 5.

  As shown in FIG. 2B, the diaphragm 8 has a substantially annular shape and a step-like cross-sectional shape, and a first fitting portion 8 a that fits the first support portion 7 ca of the drive cone 7; And a second fitting portion 8c that fits into the second support portion 7da of the drive cone 7. As shown in FIGS. 1 and 2B, the first fitting portion 8 a is provided on the inner peripheral portion of the diaphragm 8 and is fitted to the first support portion 7 ca of the drive cone 7. As shown in FIGS. 1 and 2B, the second fitting portion 8c is provided at the center of the diaphragm 8, above the first fitting portion 8a, and inside the outer peripheral portion 8b of the diaphragm 8. And is fitted to the second support portion 7 da of the drive cone 7. Further, in the diaphragm 8, the diameter d2 that defines the effective vibration area that contributes to vibration is set to be larger than the diameter d1 that defines the effective vibration area of the drive cone 7 that contributes to vibration.

  The first edge 9 has a substantially annular shape and a substantially semicircular cross-sectional shape. The first edge 9 is arranged so as to protrude to the magnetic circuit 30 side, the inner peripheral portion of the first edge 9 is attached to the outer peripheral portion 7b of the drive cone 7, and the first edge 9 9 is attached to the frame 12. Thereby, the first edge 9 has a role of elastically supporting the drive cone 7. In the present invention, the protruding direction of the first edge 9 may be set to the acoustic radiation direction Y1.

  The second edge 10 has a substantially annular shape and a substantially semicircular cross-sectional shape. The second edge 10 is disposed so as to protrude in the acoustic radiation direction Y1, and the inner peripheral portion of the second edge 10 is attached to the outer peripheral portion 8b of the diaphragm 8, and the second edge 10 10 is attached to the upper end of the frame 12. In the present invention, the protruding direction of the second edge 10 may be set in the direction opposite to the acoustic radiation direction Y1. Thereby, the second edge 10 has a role of elastically supporting the diaphragm 8. A gasket 13 having a substantially annular shape is attached on the outer peripheral portion of the second edge 10.

  The cap 11 has a substantially disk shape. The cap 11 is provided so as to cover the upper end portion side of the voice coil bobbin 5 located in the acoustic radiation direction Y1, and the outer peripheral portion thereof is attached to the inner peripheral portion of the diaphragm 8. Accordingly, the cap 11 has a role of preventing dust, water droplets, and the like from entering the speaker device 100.

(Frame structure)
The frame 12 has a substantially bowl shape and has a role of supporting the magnetic circuit 30 and the vibrating body 31. The frame 12 is disposed so as to surround the magnetic circuit 30 and the vibrating body 31. The frame 12 is preferably formed of a metal material such as aluminum or a resin material. Thereby, the shaping | molding process of the flame | frame 12 becomes easy.

  In the speaker device 100 having the above configuration, the audio current output from the output wiring on the amplifier side is input to the voice coil 6 through the speaker terminal 17 and the pair of plus / minus leads of the voice coil 6. Accordingly, an electromagnetic force (Lorentz force) acts on the voice coil 6 in the magnetic gap 32 based on Fleming's left-hand rule, and the drive cone 7 and the diaphragm 8 together with the voice coil 6 are in the acoustic radiation direction Y1 and vice versa. By moving in the direction, a sound wave is emitted from the diaphragm 8 in the acoustic radiation direction Y1.

(Sound characteristic variable structure of the speaker device)
Next, with reference to FIG. 1 etc., the acoustic characteristic variable structure of the speaker device 100 which is a feature of the present embodiment will be described.

  As shown in FIG. 1, in the speaker device 100, a space S <b> 1 is formed between the drive cone 7, the diaphragm 8, the first edge 9, the second edge 10, and the frame 12. Yes. In the speaker device 100, when the vibrating body 31 moves in the acoustic radiation direction Y1, the volume of the space S1 increases (expands), and the pressure in the space S1 decreases, while the vibrating body 31 moves in the acoustic radiation direction. When moving in the direction opposite to Y1, the volume of the space S1 decreases (compresses) and the pressure of the space S1 increases. Thereby, the air existing in the space S1 functions as an air spring that elastically supports the vibrating body 31. Therefore, in the speaker device 100, the vibrating body 31 is elastically supported by the elastic force of the springs of the first edge 9 and the second edge 10 and the elastic force of the air spring regulated by the volume of the space S1. Is done. Thereby, in this speaker apparatus 100, since it becomes unnecessary to provide a damper, it can contribute to size reduction and thickness reduction of a speaker apparatus. Further, in this speaker device 100, the drive cone 7 attached coaxially to the diaphragm 8 can be formed of the same material as the diaphragm 8, and mechanical fatigue is less likely to occur compared to a damper. The lowering of the support function of the diaphragm 8 due to mechanical fatigue of the component parts can be prevented, and the life of the speaker device 100 can be extended.

  Here, the stiffness of the air spring existing in the space S1 decreases as the difference in the effective vibration area between the drive cone 7 and the diaphragm 8 decreases, and as the volume of the space S1 increases.

  Therefore, in this type of speaker device, when it is necessary to reduce the stiffness of the air spring existing in the space S1, the drive is performed by increasing the diameter d1 that defines the effective vibration area of the drive cone 7 that contributes to vibration. The difference in effective vibration area between the cone 7 and the diaphragm 8 is reduced, or the length d3 of the drive cone 7 in the central axis L1 direction and the length d4 of the diaphragm 8 in the central axis L1 direction are increased in FIG. It is effective to adopt a method such as increasing the volume of the space S1. However, as described above, the speaker device is required to be thin and small, and it is difficult to adopt such a method. That is, there is a limit to changing the elastic force of the air spring existing in the space S1 by such a method, but if the substantial volume of the space S1 can be changed by any method, this is accompanied. The compliance of the air spring existing in the space S1 (the reciprocal of the stiffness of the air spring existing in the space S1) can be changed, and the elastic force of the air spring existing in the space S1 can be changed.

  Therefore, in this embodiment, paying attention to this point, in this speaker device, as shown in FIG. 1, a space S1 and an external space (a space existing outside the speaker device 100) S2 are formed with respect to the frame 12. An opening 12a for communication is provided. In this speaker device, the size of the space S1 is substantially changed by appropriately changing the size (area) A1 of the opening 12a in accordance with the specifications. Thereby, the compliance of the air spring which exists in space S1 is changed, and the design freedom of the acoustic characteristic of the speaker apparatus 100 is enlarged. This point will be described with reference to FIG.

  FIG. 3 shows a configuration of a mechanical equivalent circuit 90 of the speaker device 100 according to the present embodiment.

In FIG. 3, the vibration speed of the voice coil 6 is V, the driving force 91 of the voice coil 6 is Fb, the mechanical equivalent mass 92 of the vibrating body 31 is Mms, the mechanical equivalent compliance 93 of the speaker device 100 is Cms, and the speaker. The equivalent mechanical resistance 94 of the device 100 is Rms, the compliance 95 of the equivalent air spring existing in the space S1 is Cc, the equivalent air resistance 96 between the space S1 and the external space S2 is Rc, and the air spring existing in the external space S2 is When the equivalent compliance 97 is C _OUT , the driving force Fb of the voice coil 6 is a series connection of the mechanical equivalent mass Mms of the vibrating body 31, the mechanical compliance Cms, and the equivalent mechanical resistance Rms, and an air spring. Equivalent Compliance Cc, Equivalent Air Resistance Rc, Equivalent Comp of Air Spring Present in External Space S2 It expressed as a mechanical equivalent circuit equation parallel connection and the series-connection of the Alliance C _out. The mechanical equivalent circuit equation is specifically expressed by the following equation.

なお、「振動体３１の機械的な等価質量Ｍｍｓ」は、ボイスコイルボビン５、ボイスコイル６、ドライブコーン７、振動板８、第１のエッジ９、第２のエッジ１０及びキャップ１１の総重量である。また、「機械的な等価コンプライアンスＣｍｓ」は、スピーカー装置１００の機械的な構成要素のスチフネスの総和の逆数である。また、「等価機械抵抗Ｒｍｓ」は、振動体３１が動くときに生じる機械的な抵抗である。また、「空気バネの等価コンプライアンスＣｃ」は、空間Ｓ１に存在する空気バネのスチフネスの逆数である。また、「等価空気抵抗Ｒｃ」は、空間Ｓ１と外部空間Ｓ２との間において空気が吸入又は排出されるときに生じる空気抵抗である。

The “mechanical equivalent mass Mms of the vibrator 31” is the total weight of the voice coil bobbin 5, the voice coil 6, the drive cone 7, the diaphragm 8, the first edge 9, the second edge 10 and the cap 11. is there. “Mechanical equivalent compliance Cms” is the reciprocal of the sum of stiffness of the mechanical components of the speaker device 100. The “equivalent mechanical resistance Rms” is a mechanical resistance generated when the vibrating body 31 moves. The “equivalent compliance Cc of the air spring” is the reciprocal of the stiffness of the air spring existing in the space S1. The “equivalent air resistance Rc” is an air resistance generated when air is sucked or discharged between the space S1 and the external space S2.

The “equivalent compliance C _out of the air spring in the external space S2” is an equivalent compliance when the air in the external space S2 is considered to have developed the function of a spring (hereinafter referred to as “air spring”). . Since the volume of the external space S2 is so large, equivalent compliance C _out of the air spring in the external space S2 is a very large size. Therefore, from the above equation 1, since the equivalent mechanical impedance (= 1 / jωC _out ) of the air spring existing in the external space S2 becomes very small, the above-described equivalent circuit 90 is equivalent to the equivalent compliance C of the air spring in the external space S2. It becomes almost short-circuited at _out .

  Therefore, in the speaker device 100, the magnitude of the equivalent air resistance Rc can be changed in the mechanical equivalent circuit 90 by changing the size (area) A1 of the opening 12a. As a result, the equivalent compliance Cc of the air spring existing in the space S1 can be changed, and the elastic force of the air spring existing in the space S1 can be changed.

Specifically, when the size (area) A1 of the opening 12a is increased in the speaker device 100, the equivalent air resistance Rc is reduced accordingly when the speaker device 100 is driven, so that the space S1 and the external space S2 are reduced. The air is easily sucked and discharged. Thus, the contribution of the equivalent compliance C _C decreases, the transition to the direction in which ineffective is equivalent compliance Cc air spring existing in the space S1, the elastic force of the air spring existing in the space S1 is reduced, along with this Thus, the vibrating body 31 is easy to move. On the other hand, when the size (area) A1 of the opening 12a is reduced in the speaker device 100, the equivalent air resistance Rc increases accordingly when the speaker device 100 is driven. It is difficult for air to be sucked into and discharged from S2. Thus, the contribution of the equivalent compliance C _C increases, the transition to the direction of chrysanthemum equivalent compliance Cc air spring existing in the space S1, the elastic force of the air spring existing in the space S1 increases, along with this The vibrating body 31 becomes difficult to move.

  As described above, in this speaker device 100, the size of the volume of the space S1 is substantially changed by appropriately changing the size (area) A1 of the opening 12a provided in the frame 12 according to the specifications. Can be changed. As a result, the equivalent compliance Cc of the air spring existing in the space S1 can be changed, and the elastic force of the air spring existing in the space S1 can be changed. Therefore, the acoustic characteristic can be easily changed to a desired characteristic, and the design flexibility of the acoustic characteristic can be improved.

  Further, when assuming a configuration in which the opening 12a is closed in the speaker device 100 (hereinafter referred to as “comparative example”), the space S1 is a sealed space. Then, in the comparative example, the pressure in the sealed space S1 changes when the speaker device is not driven due to the temperature change or the atmospheric pressure change between the sealed space S1 and the external space S2. Due to the action of the air spring existing in the space S1 due to the change, there arises a problem that the vibrating body 31 moves freely in the direction of the central axis L1.

  Specifically, in the comparative example, the effective vibration area of the diaphragm 8 that contributes to vibration is set larger than the effective vibration area of the drive cone 7 that contributes to vibration. For this reason, the air pressure in the sealed space S1 decreases due to a change in temperature or a change in atmospheric pressure between the sealed space S1 and the external space S2 (that is, the volume of the sealed space S1 increases). Then, after the driving of the speaker device is stopped, there is a problem that the vibrating body 31 moves freely in the acoustic radiation direction Y1 by the action of the air spring existing in the space S1 generated by the pressure change. . On the other hand, when the pressure in the sealed space S1 increases (that is, the volume of the sealed space S1 decreases) due to such a change in temperature or a change in atmospheric pressure, the speaker device After stopping the driving, there arises a problem that the vibrating body 31 moves freely in the direction opposite to the acoustic radiation direction Y1 due to the action of the air spring existing in the space S1 generated by the pressure change. For this reason, in the comparative example, when a change in temperature or a change in atmospheric pressure occurs between the space S1 and the external space S2, it is difficult to hold the vibrating body 31 at a predetermined stationary position. There is.

  In this respect, in the present embodiment, as described above, the space S1 and the external space S2 communicate with each other through the opening 12a provided in the frame 12, and therefore, the temperature change between the space S1 and the external space S2. Alternatively, even when the atmospheric pressure changes, the air pressure in the space S1 hardly changes after the driving of the speaker device 100 is stopped, so that the vibrating body 31 moves freely in the direction of the central axis L1. Such a problem can be prevented. Further, even if the size (area) A1 of the opening 12a is set to be small in this embodiment, such a change in temperature or a change in atmospheric pressure is slow in time. Since the space S1 does not become a sealed state due to a change in temperature or pressure, the air pressure in the space S1 hardly changes, and there is a problem that the vibrating body 31 moves freely in the direction of the central axis L1. It can be prevented from occurring. Therefore, in the present embodiment, the vibrating body 31 can be held at a specified stationary position even when a change in temperature or a change in atmospheric pressure occurs between the space S1 and the external space S2.

  In the above embodiment, it is preferable that an acoustic resistance member (not shown) is attached to the opening 12a. Here, as an acoustic resistance member, the fiber material comprised from well-known fibers, such as glass wool and a nonwoven fabric, is mentioned, for example. As a result, after the speaker device 100 is manufactured, the amount of the acoustic resistance member inserted into the opening 12a, the material, dimensions, and shape of the acoustic resistance member inserted into the opening 12a can be changed afterwards. It is possible to change the aperture ratio of the acoustic resistance member by forming it in the acoustic resistance member or providing a large number of such holes. Therefore, since the equivalent compliance Cc of the air spring existing in the space S1 can be easily changed, the elastic force of the air spring existing in the space S1 can be easily changed. As a result, the acoustic characteristics can be changed to desired characteristics afterwards.

[Modification 1]
In the speaker device 100 according to the above embodiment, the frame 12 has the space S <b> 1 formed between the drive cone 7, the diaphragm 8, the first edge 9, the second edge 10, and the frame 12. And an external space S2 and an opening 12a for varying the equivalent compliance Cc of the air spring existing in the space S1.

  In the present invention, the present invention is not limited to this, and the space S1 and the external space S2 formed between the drive cone 7, the diaphragm 8, the first edge 9, the second edge 10, and the frame 12 are included. The opening for communicating and changing the equivalent compliance Cc of the air spring existing in the space S1 includes the drive cone 7, the diaphragm 8, the first edge 9, the second edge 10, and the frame 12. It suffices if it is provided on at least one member. In the present embodiment, the frame 12 has an opening (not shown) that communicates with the space between the drive cone 7 and the magnetic circuit 30 and the external space S2. Thereby, in the modification 1, the magnitude | size of the volume of space S1 can be changed substantially by changing suitably the magnitude | size (area) of the opening part provided in the said at least 1 member. As a result, the equivalent compliance Cc of the air spring existing in the space S1 can be changed, and the elastic force of the air spring existing in the space S1 can be changed. Therefore, the acoustic characteristic can be easily changed to a desired characteristic, and the design flexibility of the acoustic characteristic can be improved.

  For example, as one form of the speaker device 100 according to the modified example 1, as shown in FIG. 4, the second edge 10 communicates with the space S <b> 1 and the external space S <b> 2 and the air existing in the space S <b> 1. A plurality of openings 10a for changing the equivalent compliance Cc of the spring are provided at appropriate intervals in the circumferential direction. FIG. 4 is a plan view of the speaker device 100 according to one form of Modification 1 when viewed from the direction opposite to the acoustic radiation direction Y1. As a result, the space S1 and the external space S2 communicate with each other through the opening 10a of the second edge 10. Therefore, the equivalent compliance Cc of the air spring existing in the space S1 can be changed by appropriately changing the number and size of the openings 10a provided in the second edge 10 according to the specifications of the speaker device 100. The elastic force of the air spring existing in the space S1 can be changed. Therefore, the acoustic characteristic can be easily changed to a desired characteristic, and the design flexibility of the acoustic characteristic can be improved.

  Further, in another form of the speaker device 100 according to the modified example 1, the second edge 10 is not provided with the opening 10a, but is made of a film-like material having air permeability (for example, urethane or the like). 2 edges 10 are formed. As a result, the space S1 and the external space S2 communicate with each other through the second edge 10. Therefore, the equivalent compliance Cc of the air spring existing in the space S1 is changed by appropriately changing the air-permeable film-like material for forming the second edge 10 according to the specifications of the speaker device 100. And the elastic force of the air spring existing in the space S1 can be changed. Therefore, the acoustic characteristic can be easily changed to a desired characteristic, and the design flexibility of the acoustic characteristic can be improved.

  Further, in still another embodiment of the speaker device 100 according to the first modification, the opening 10a is not provided for the second edge 10, but the second edge 10 corresponds to the opening 10a of FIG. A ventilation portion made of a material having air permeability and low air resistance is provided at the position. As a result, the space S1 and the external space S2 communicate with each other through the ventilation portion of the second edge 10. Therefore, according to the specifications of the speaker device 100, the equivalent compliance Cc of the air spring existing in the space S1 can be changed by appropriately changing the material, number, size, and the like of the ventilation portion of the second edge 10. The elastic force of the air spring existing in the space S1 can be changed. Therefore, the acoustic characteristic can be easily changed to a desired characteristic, and the design flexibility of the acoustic characteristic can be improved.

[Modification 2]
In the case of the above embodiment, it is difficult to change the size (area) A1 of the opening 12a after the speaker device 100 is manufactured.

  Therefore, the frame 12 according to the modified example 2 has an opening 12bx that communicates with the space S1 and the external space S2 and changes the equivalent compliance Cc of the air spring that exists in the space S1, as shown in FIG. A cylindrical cylindrical portion 12b is provided, and an acoustic resistance member 14 having air permeability is provided in the opening portion 12bx so that air does not escape too much. Here, examples of the acoustic resistance member 14 include glass wool and non-woven fabric. Accordingly, after the speaker device 100 is manufactured, the amount of the acoustic resistance member 14 to be inserted into the opening 12bx of the cylindrical portion 12b, the material of the acoustic resistance member 14 to be inserted into the opening 12bx, or the like can be changed afterwards. It becomes possible. Thereby, the equivalent compliance Cc of the air spring existing in the space S1 can be easily changed, and the elastic force of the air spring existing in the space S1 can be easily changed. As a result, the acoustic characteristics can be changed to desired characteristics afterwards.

[Modification 3]
In view of the fact that it is difficult to change the size (area) A1 of the opening 12a after manufacturing the speaker device 100 as described above, the third modification corresponds to the opening 12a of the frame 12. An opening variable mechanism is provided for changing the size (area) A1 of the opening 12a with respect to the position. An example of this is shown in FIGS.

  FIG. 6 is a cross-sectional view of the speaker device 100 according to the third modification corresponding to FIG. FIG. 7A shows a side view of the speaker device 100 when viewed from the direction of the arrow Y3 in FIG. 6 (that is, when the opening 12a and the opening variable mechanism 15 are viewed from the front), and in particular, the opening 12a. Shows a state in which is not closed by the closing member 15 a of the opening variable mechanism 15. FIG. 7B shows a side view of the speaker device 100 corresponding to FIG. 7A, and particularly shows a state when the opening 12 a is completely closed by the closing member 15 a of the opening changing mechanism 15. . FIG. 7C shows a side view of the speaker device 100 corresponding to FIG. 7A, and particularly when the opening 12 a is closed by a predetermined ratio by the closing member 15 a of the opening changing mechanism 15. Indicates.

  As shown in FIGS. 6 and 7, in the third modification, the size of the opening 12a (on the outer space S2 side) is a position corresponding to the opening 12a of the frame 12 and outside the frame 12 (external space S2 side). An opening variable mechanism 15 for changing the area A1 is provided. The opening variable mechanism 15 includes a closing member 15a for closing the opening 12a, and a slide mechanism 15b capable of moving the closing member 15a in the opening / closing direction of the opening 12a. Therefore, in modification 3, according to the specification of the speaker device 100, the opening 12a can be fully closed or closed at a predetermined rate by sliding the closing member 15a toward the opening 12a later. become. On the contrary, by sliding the closing member 15a in the state of closing the opening 12a to the slide mechanism 15b side, the opening 12a can be fully opened or opened at a predetermined rate.

  This makes it easy to change the size (area) A1 of the opening 12a through the opening varying mechanism 15 after the speaker device 100 is manufactured. Therefore, the equivalent compliance Cc of the air spring existing in the space S1 can be easily changed, and the elastic force of the air spring existing in the space S1 can be easily changed. As a result, the acoustic characteristics can be changed to desired characteristics afterwards.

  In addition, the present invention is not limited to this, and as another form of the modified example 3, as shown in FIG. 8, the position is a position corresponding to the opening 12a of the frame 12 and the inside of the frame 12 (space S1 side). ), The opening variable mechanism 15 for changing the size (area) A1 of the opening 12a may be provided.

[Modification 4]
In view of the fact that it is difficult to change the size (area) A1 of the opening 12a after the speaker device 100 is manufactured as described above, the fourth modification is the same as the third modification described above. 9A, the opening 12a is closed by a lid body 16 having at least one hole 16a, and the lid body 16 covers the opening member 15a of the opening 12a. It is opened and closed by moving in the opening and closing direction. FIG. 9A shows a side view of the speaker device 100 according to one form of the modification 4 corresponding to FIG. 7A, and in particular, the lid body 16 is closed by the closing member 15 a of the opening variable mechanism 15. Shows the state when not done. Thus, after the speaker device 100 is manufactured, the size of the opening 12a is indirectly increased by changing the size (area) of closing the lid 16 by the closing member 15a of the opening changing mechanism 15 afterwards. The length (area) A1 can be changed.

  In the present invention, as shown in FIG. 9B, the opening 12a has a circular shape, and the opening 12a is closed by a semicircular lid 16 having at least one hole 16a. The opening variable mechanism 15 is provided at a position corresponding to the opening 12a, and has a semicircular blocking member 15a for closing the opening 12a via the lid 16, and the opening member 15a is connected to the opening 12a. And a slide mechanism 15bx that can be moved in the opening / closing direction (rotation direction) of 12a. The slide mechanism 15bx supports the closing member 15a so as to be movable in the opening / closing direction (rotating direction) of the opening 12a with the rotating portion 15c as an element as a base point. FIG. 9B shows a side view of the speaker device 100 according to another form of the modification 4 corresponding to FIG. 7A, and in particular, the lid 16 is predetermined by the closing member 15 a of the opening variable mechanism 15. It shows the state when it is blocked by the rate of. With such a structure, after the speaker device 100 is manufactured, the size (area) of closing the lid 16 is changed by the closing member 15a of the opening variable mechanism 15 afterwards, thereby indirectly adjusting the opening 12a. The size (area) A1 can be changed. Furthermore, the acoustic characteristic can be changed to a desired characteristic by changing the air resistance by changing the size and number of the holes 16a of the lid body 16.

  Therefore, according to these configurations, it becomes easy to change the size (area) A1 of the opening 12a through the opening changing mechanism 15 after the speaker device 100 is manufactured. Thereby, the equivalent compliance Cc of the air spring existing in the space S1 can be easily changed, and the elastic force of the air spring existing in the space S1 can be easily changed. As a result, the acoustic characteristics can be changed to desired characteristics afterwards.

Sectional drawing of the speaker apparatus which concerns on the Example of this invention. Sectional drawing of the drive cone and diaphragm which concern on a present Example. The mechanical equivalent circuit schematic of the speaker apparatus which concerns on a present Example. The top view of the speaker apparatus which concerns on one form of the modification 1. FIG. Sectional drawing of the speaker apparatus which concerns on the modification 2. FIG. Sectional drawing of the speaker apparatus which concerns on the modification 3. FIG. The various side views of the speaker apparatus which concerns on the modification 3. FIG. Sectional drawing of the speaker apparatus which concerns on the other form of the modification 3. FIG. The side view of the speaker apparatus which concerns on the various form of the modification 4. FIG. The graph explaining the linearity characteristic of the edge which concerns on a prior art.

Explanation of symbols

7 drive cone 8 diaphragm 9 first edge 10 second edge 12 frame 12a opening 12b cylindrical portion 12bx opening 14 acoustic resistance member 15 opening variable mechanism 15a closing member 15b slide mechanism 16 lid 16a hole 30 magnetic circuit 31 Vibrating body 90 Equivalent circuit 95 Equivalent compliance Cc of air spring
96 Equivalent air resistance Rc
100 Speaker device S1 space S2 External space

Claims (9)

A vibrator, and a support that supports the vibrator,
A space is formed between the vibrating body and the support,
The air present in the space has a function of an air spring that elastically supports the vibrating body,
At least one of the members constituting the vibrating body and the support is provided with an opening communicating with the space and the external space and for varying the compliance of the air spring existing in the space. The speaker device characterized by being made.   The speaker device according to claim 1, wherein the compliance of the air spring existing in the space is varied by changing a size of the opening.   The speaker device according to claim 1, wherein an acoustic resistance member is attached to the opening. The support includes a cylindrical cylindrical portion having the opening,
The speaker device according to claim 1, wherein an acoustic resistance member having air permeability is provided in the opening.   The speaker device according to claim 1, wherein an opening variable mechanism for changing a size of the opening is provided at a position corresponding to the opening.   5. The opening variable mechanism includes a closing member for closing the opening, and a slide mechanism capable of moving the closing member in an opening / closing direction of the opening. The speaker device according to 1. The opening is closed by a lid having at least one hole;
The speaker device according to claim 4 or 5, wherein the lid is opened and closed by moving the closing member in an opening and closing direction of the opening. The vibrator has a diaphragm and an edge that elastically supports the diaphragm,
The speaker device according to claim 1, wherein the opening is provided in at least one member among members constituting the diaphragm, the edge, and the support. The support is disposed so as to surround the vibrating body;
The vibrator includes a voice coil, a voice coil bobbin around which the voice coil is wound,
A diaphragm elastically supported by the support, a drive cone transmitting vibrations of the voice coil to the diaphragm, a first edge elastically supporting the drive cone, and the diaphragm elastically A second edge that supports
The space is formed between the drive cone, the diaphragm, the first edge, the second edge, and the support,
The opening is provided in at least one member among members constituting the drive cone, the diaphragm, the first edge, the second edge, and the support. The speaker device according to 1.

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