JP2012169901A - Electro-dynamic exciter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electro-dynamic exciter which makes the deterioration of electro-acoustic conversion characteristics and damage due to contacts less likely to be caused even when mounted on a vertical wall in a vertical manner and concurrently improves low frequency characteristics in the electro-acoustic characteristics.SOLUTION: An electro-dynamic exciter includes: a bowl-shaped outer yoke; a magnet circuit part including a magnet disposed so as to be enclosed by the bowl-shaped outer yoke and an inner yoke; a coil disposed in a magnetic gap formed in the magnet circuit part; a diaphragm to which the coil is fixed; and elastic bodies elastically connecting the diaphragm with the magnet circuit part so as to form a predetermined space between the diaphragm and the magnet circuit part. The elastic bodies are composed of at least two elastic bodies, a first elastic body and a second elastic body, and the first elastic body and the second elastic body connect an area near an outer periphery of the outer yoke with an area near an outer periphery of the diaphragm so as to generate pressing forces opposing each other in the axial direction that is the vibration direction of the diaphragm.

Description

  The present invention is an electromotive exciter that is applied to a thin panel speaker that is used to reduce the thickness of various electronic devices such as a television and a personal computer, or that is applied to generation of a notification sound by being attached to an electric vehicle or the like. Is related to the structure of

  Conventionally, electromotive exciters have been widely used for thin panel speakers mounted on home appliances such as thin liquid crystal televisions, thin plasma televisions, thin personal computers, and various monitor devices for industrial machine tools. That is, the conventional electrodynamic exciter is composed of a saddle-shaped inner yoke, a permanent magnet, an outer yoke, a voice coil, a diaphragm, and an adhesive member, and the voice coil is located in the gap between the inner yoke and the outer yoke side wall. The diaphragm is fixed integrally with the voice coil. A diaphragm in which a voice coil vibrates in the axial direction by passing a current consisting of a predetermined signal through a voice coil in a magnetic circuit composed of a permanent magnet, an inner yoke and an outer yoke, and the voice coil is integrally fixed. A sound wave is emitted by exciting the.

  For example, an electrodynamic exciter according to Patent Document 1 is integrated with a voice coil on an axial end surface of a magnetic circuit composed of an inner yoke, a magnet, and an outer yoke by means of an elastic holding body such as foamed urethane. It has a structure in which a vibration member made of a fixed diaphragm is adhered.

  In addition, an electrodynamic exciter according to Patent Document 2 includes a magnetic circuit composed of a bowl-shaped outer yoke, a plate-shaped magnet and an inner yoke that are sequentially stacked inside the outer yoke, and an outer portion of the magnetic circuit. A voice coil disposed in a gap formed between the inner peripheral portion of the side wall of the yoke and the outer peripheral portion of the inner yoke, and a sub-panel corresponding to a diaphragm that holds the voice coil in front of the magnetic circuit, The magnetic circuit has a structure in which the vicinity of the center of gravity in the thickness direction and the sub-panel are held by a plurality of arc-shaped strip-shaped thin plate elastic holders.

JP-A-10-243491 JP 2003-143690 A

  These conventional electrodynamic exciters are widely used in electronic devices such as thin televisions and thin personal computers. In particular, these thin speakers for home appliances are becoming increasingly competitive in the market due to their small size, light weight, thin shape, and low price. From the standpoint of product differentiation, it is essential to improve acoustic performance in the low frequency range. The improvement proposal is made by such as.

When the diaphragm of the electrodynamic exciter disclosed in Patent Document 1 is mounted in a horizontal state, no problem occurs, but when the diaphragm is mounted in an upright state, the entire weight of the exciter's magnetic circuit is elastically retained. Acts in the direction of body shear. For this reason, the lower the elastic constant of the elastic holder is, the larger the axial misalignment of the voice coil and the axial center of the magnetic circuit and the tilt of the axial center are, and the air gap around the voice coil changes. There has been a problem that the characteristics change and the necessary frequency characteristics cannot be obtained.

  Further, in home appliances such as a television and a personal computer, the vibration of the main body is very small, so that the vibration durability required for the home appliance speaker hardly poses a problem. However, in the case of a vehicle-mounted speaker mounted on a moving body with large vibration such as an automobile, when the exciter diaphragm is mounted in an upright state, the elastic holder is not only a static shear stress due to the weight of the magnetic circuit, Dynamic alternating shear stress due to vibration of the exciter mounting part is also added, so the exciter can be mounted such that the shear stress for in-vehicle use is significantly larger than when the exciter is mounted on home appliances, and the elastic holder is destroyed. Depending on the direction, there was a problem that the reliability was greatly reduced.

  Patent Document 2 discloses a means for improving the problem of Patent Document 1. In Patent Document 2, the structure of supporting the vicinity of the center of gravity in the thickness direction of the magnetic circuit with an elastic holding body made of a thin metal plate makes it possible to deteriorate the electrical / acoustic conversion characteristics even when the diaphragm is mounted upright. In addition, there is disclosed an exciter (speaker) that is less likely to be damaged due to contact and that has excellent seismic resistance that can operate even in a vibration environment such as in-vehicle use.

  According to this structure, when the diaphragm is mounted in an upright state, the rotational moment due to the weight of the magnetic circuit can be reduced. However, the belt-like thin plate elastic holder does not have a security function and has a drawback that a waterproof structure cannot be obtained. is there. Therefore, when the exciter having such a structure is installed outside the passenger compartment, the voice coil may be damaged when moisture enters the voice coil portion.

  The present invention has been made in order to solve the problems of the electrodynamic exciter used as a conventional thin speaker as described above, and has an electrical / acoustic conversion characteristic even when mounted vertically on a vertical wall surface. It is an object of the present invention to provide an electrodynamic exciter that is less likely to be deteriorated or damaged by contact, and at the same time, can improve low frequency characteristics in terms of electrical / acoustic characteristics.

  The present invention includes a hook-shaped outer yoke, a magnetic circuit section including a magnet and an inner yoke disposed between the hook-shaped outer yokes, and a magnetic gap formed in the magnetic circuit section. And a diaphragm having the coil fixed thereto, and an elastic body that elastically connects the diaphragm and the magnetic circuit unit so that the diaphragm and the magnetic circuit unit have a predetermined gap. In the electric exciter, the elastic body is composed of at least two elastic bodies, a first elastic body and a second elastic body, and the first elastic body and the second elastic body are formed of the diaphragm. The vicinity of the outer periphery of the outer yoke and the vicinity of the outer periphery of the diaphragm are connected so as to generate mutually opposite pressing forces in the axial direction that is the vibration direction.

  According to the present invention, even when mounted on a vertical wall surface in a vertical state, the electro-electric exciter is less likely to cause deterioration in electrical / acoustic conversion characteristics and damage due to contact, and at the same time, can improve low-frequency characteristics in electrical / acoustic characteristics. Is obtained.

It is typical sectional drawing which shows the structure of the electrodynamic exciter by Embodiment 1 of this invention. It is typical sectional drawing of the state which laid the electrodynamic exciter by Embodiment 1 of this invention on the vertical wall surface. It is a fragmentary sectional view which shows the structure of the principal part of the electrodynamic exciter by Embodiment 1 of this invention. It is a perspective view which shows the external appearance of the whole electrodynamic exciter by Embodiment 1 of this invention. It is a schematic diagram which shows the relationship of the spring constant of the structure of the electrodynamic exciter by Embodiment 1 of this invention. It is a fragmentary sectional view which shows the structure of the principal part of the electrodynamic exciter by Embodiment 2 of this invention. It is a fragmentary sectional view which shows the structure of the principal part of the electrodynamic exciter by Embodiment 3 of this invention. It is a fragmentary sectional view which shows the structure of the principal part of the electrodynamic exciter by Embodiment 4 of this invention. It is a fragmentary sectional view which shows the structure of the principal part of the electrodynamic exciter by Embodiment 5 of this invention. It is a perspective view which shows the external appearance of the whole electrodynamic exciter by Embodiment 6 of this invention. It is sectional drawing which shows the structure of the electrodynamic exciter by Embodiment 7 of this invention.

Embodiment 1 FIG.
FIG. 1 is a schematic cross-sectional view showing a configuration of an electrodynamic exciter according to Embodiment 1 of the present invention. 2 is a schematic cross-sectional view of the state in which the electrodynamic exciter of FIG. 1 is laid on a vertical wall surface, and FIG. 3 is a schematic cross-sectional view of the electrodynamic exciter according to Embodiment 1 of the present invention. It is a fragmentary sectional view which expands and shows the inside of the broken-line circle | round | yen in FIG. FIG. 4 is a perspective view showing the overall appearance of the electrodynamic exciter according to Embodiment 1 of the present invention. 1, 2, and 3, a magnetic circuit is constituted by an inner yoke 1 made of a magnetic material, a flat magnet 2 made of a rare earth, and an outer yoke 3 made of a bowl-shaped magnetic material. One side of the magnet 2 is in contact with the inner bottom surface of the bowl of the outer yoke 3, and the other side of the magnet 2 is in contact with the inner yoke 1 made of a magnetic material. The outer yoke 3, the magnet 2 and the inner yoke 1 are joined together by an adhesive (not shown), and a gap (gap) is formed between the radially outer peripheral surface of the inner yoke 1 and the inner peripheral wall surface of the outer edge of the outer yoke 3. The magnetic circuit is configured by holding it.

  A coil 5 wound around a bobbin 4 made of an insulating material is disposed so as to be positioned in a gap portion (gap) of the magnetic circuit, and the bobbin 4 around which the coil 5 is wound is integrated by a thin flat diaphragm 6. Is held.

  The outer yoke 3 has a stepped portion 31 projecting in the radial direction at the center of the outer wall surface in the axial direction of the electrodynamic exciter (hereinafter simply referred to as the axial direction). The facing side has a convex portion 32. The diaphragm 6 has a frame portion 61 that protrudes in the axial direction so as to face the convex portion 32 provided on the stepped portion 31 of the outer yoke 3 in the vicinity of the outer peripheral portion.

  A ring-shaped elastic body (first elastic body) 7 is disposed in a state of being sandwiched between the stepped portion 31 of the outer yoke 3 and the radial end portion of the diaphragm 6. Further, the first elastic body 7 has an H shape in which grooves having a predetermined width and depth are formed on both end faces in the axial direction, and a convex portion provided on the stepped portion 31 of the outer yoke 3. 32 and a frame portion 61 provided in the vicinity of the outer peripheral portion of the diaphragm 6 are engaged with grooves formed on both end surfaces of the first elastic body 7 in the axial direction.

  A ring-shaped elastic body (second elastic body) 8 having a U-shaped cross-sectional shape is fitted so as to press the stepped portion 31 of the outer yoke 3 and the radial end portion of the diaphragm 6 in the approaching direction. Yes. In addition, it is more preferable that the fitting portion between the stepped portion 31 of the outer yoke 3 and the outer peripheral portion of the diaphragm 6 prevent the unillustrated stopper so that the second elastic body 8 is not easily detached.

  The outer appearance of the outer yoke 3 and the second elastic body 8 of the first embodiment are both cylindrical as shown in FIG. 4, but the electrodynamic exciter to which the present invention can be applied is a cylinder. The shape is not limited.

  The electrodynamic exciter configured as described above includes an outer yoke 3 constituting a magnetic circuit and a diaphragm 6 excited by energization of the coil 5, a first elastic body 7 and a second elastic body 8. The spring constants of both elastic members are set so that the axial pressing force of the first elastic body 7 and the pressing force of the second elastic body 8 are balanced at a predetermined value.

  FIG. 5 is a schematic diagram for explaining the relationship between the spring constants of both elastic bodies. In the figure, Kc represents the spring constant of the first elastic body 7 that generates a pressing force by being deformed in the compression direction. , Ke indicates a spring constant of the second elastic body 8 in which a pressing force is generated by deformation in the pulling direction. Further, in a state where the first elastic body 7 and the second elastic body 8 are provided, a predetermined gap L is provided between the axial end surface of the outer yoke 3 constituting the magnetic circuit portion and the diaphragm 6. Yes.

  When the electrodynamic exciter is driven in this state, the diaphragm 6 is relatively displaced with respect to the outer yoke 3, so that the gap L shown in FIG. 5 increases or decreases by the dynamic amplitude change of the diaphragm 6. . Therefore, it is necessary to set the gap L within a predetermined range so that the diaphragm 6 and the outer yoke 3 do not come into contact with each other even when the maximum power supply of the electrodynamic exciter is driven. Therefore, in order to ensure the predetermined gap L at a position where the axial pressing force of the first elastic body 7 and the axial pressing force of the second elastic body 8 are in an equilibrium state, the first elastic body 7 It is desirable to reduce the difference between the axial spring constant Kc of the second elastic body 8 and the axial spring constant Ke of the second elastic body 8 as much as possible.

  Further, it is desirable that the axial spring constant Kc of the first elastic body 7 and the radial spring constant Kv orthogonal thereto are in a relationship of Kc << Kv, and the difference is within a range that does not disturb the vibration of the diaphragm 6. To set as large as possible. When the axis of the electrodynamic exciter is tilted with respect to the gravity axis or mounted in a horizontal state, the weight of the magnetic circuit occupying most of the weight of the electrodynamic exciter, that is, the inner yoke 1 and the magnet 2 and the total weight of the outer yoke 3 acts in the direction of gravity, so if the radial spring constant of the first elastic body 7 is too low, the axis of the magnetic circuit section is inclined with respect to the axis of the diaphragm 6, and the magnetic circuit The air gap will change. As a result, an adverse effect on electrical characteristics that leads to a decrease in driving force of the electrodynamic exciter occurs. Further, when this electrodynamic exciter is used as an approach notification device such as an electric vehicle, for example, vehicle running vibration, particularly low frequency vibration, is applied, so that the bobbin 4 and the coil 5 are connected to the outer yoke 3 and the inner yoke 1. In a severe vibration environment, there is a risk of causing a fatal problem due to the disconnection of the coil 5 or the like. Therefore, the relationship of Kc << Kv is necessary to prevent such a problem.

  In addition, when the electrodynamic exciter is used outdoors such as a sounding body for an approach notification device such as an electric vehicle, a waterproof function is required because it is exposed to the outside air. Therefore, at least one of the first elastic body 7 and the second elastic body 8 has a ring shape and needs to have a function of blocking the internal space and the outside of the electrodynamic exciter. In the first embodiment, the first elastic body 7 and the second elastic body 8 use rubber ring-shaped elastic bodies. For example, one axial end surface of the first elastic body 7 is the outer yoke 3. The stepped portion 31 is in pressure contact with the axial end surface, and the other end surface is in pressure contact with the diaphragm 6. Further, both axial ends of the second elastic body 8 are formed between the stepped portion 31 of the outer yoke and the diaphragm 6. They are pressed against each other in the form of holding the ends.

As a result, the inner space of the electrodynamic exciter is completely sealed by the pressure contact between the axial end portions of the first elastic body 7 and the second elastic body 8 and is in a state of being cut off from the atmosphere. Even an electrodynamic exciter in use has no risk of water getting inside. For this reason, poor insulation of the coil 5 and corrosion of the inner yoke 1 and the outer yoke 3 hardly occur. Accordingly, it is possible to remarkably improve the environmental resistance required as a sounding body for an approach notification device to be mounted in a severe environment such as the outside of the vehicle or under the floor.

Embodiment 2. FIG.
FIG. 6 is a partial cross-sectional view showing the configuration of the main part of the electrodynamic exciter according to the second embodiment of the present invention, which corresponds to FIG. 3 of the first embodiment. 6, the same reference numerals as those in FIG. 3 denote the same or corresponding parts. The difference between the second embodiment and the first embodiment is the cross-sectional shape of the first elastic body 7, and the cross section is rectangular. The longitudinal direction of the cross section of the first elastic body 7 is disposed so as to be sandwiched between the stepped portion 31 of the outer yoke 3 and the diaphragm 6, and corresponds to a spring indicated by a spring constant Kc in FIG. Play the role of a spring. Further, a frame portion 62 is formed by bending the outer peripheral end portion of the diaphragm 6 into a frame shape so as to surround the outer peripheral surface of the outer yoke 3. The cross-sectional short direction of the first elastic body 7 is arranged so as to be sandwiched between the surface of the frame portion 62 facing the outer peripheral surface of the outer yoke 3 and the outer peripheral surface of the outer yoke 3. It plays the role of a spring corresponding to the spring indicated by the spring constant Kv of 3. Thus, the spring constant for supporting the magnetic circuit portion of the electrodynamic exciter in the axial direction is determined by the spring constant in the longitudinal direction of the cross section of the first elastic body 7, while the direction orthogonal to the axial direction of the electrodynamic exciter That is, the spring constant supported in the radial direction is determined by the spring constant of the first elastic body 7 in the cross-sectional short direction.

  Therefore, by setting the spring constant in the longitudinal direction of the cross section of the first elastic body 7 lower, the vibration characteristics in the low frequency region of the electrodynamic exciter can be improved. In addition, when used in a state where the axis of the electrodynamic exciter is tilted from the gravity axis or the electrodynamic exciter is mounted on a vertical wall surface, the spring constant in the short direction of the cross section of the first elastic body 7 is increased. By setting, the magnetic circuit part composed of the inner yoke 1, the magnet 2 and the outer yoke 3 can be elastically supported with a high spring constant. For this reason, it is possible to prevent the axis of the magnetic circuit that occupies most of the total weight from tilting with respect to the axis of the electrodynamic exciter, and to prevent the occurrence of disconnection failure due to contact between the coil 5 and the outer yoke 3 or the like. Can do. Therefore, the reliability of the electrodynamic exciter when the vertical wall surface is mounted can be greatly improved.

Embodiment 3 FIG.
FIG. 7 is a partial cross-sectional view showing the configuration of the electrodynamic exciter according to the third embodiment of the present invention, and corresponds to FIG. 3 of the first embodiment. 7, the same reference numerals as those in FIGS. 3 and 6 denote the same or corresponding parts. The third embodiment is different from the first and second embodiments in that the first elastic body 7 is divided into two elastic bodies, and the first elastic body A72 in FIG. The elastic body B73 is provided.

  Here, the first elastic body A72 elastically supports the magnetic circuit portion in the axial direction, and the first elastic body B73 elastically supports the magnetic circuit portion in the radial direction. That is, the first elastic body A72 is disposed so as to be sandwiched between the diaphragm 6 and the stepped portion 31 of the outer yoke 3, and the outer peripheral surface of the outer yoke 3 and the end of the diaphragm 6 are bent. A gap is provided in the radial direction so that no spring force acts between the portions. Further, a frame portion 62 is formed by bending the outer peripheral end portion of the diaphragm 6 so as to surround the periphery of the protrusion 32 of the stepped portion 31 of the outer yoke. The first elastic body B73 is sandwiched between the surface of the frame portion 62 that faces the periphery of the protrusion of the stepped portion of the outer yoke 3 and the outer peripheral surface of the protrusion 32 of the stepped portion 31 of the outer yoke 3. And plays the role of a spring corresponding to the spring indicated by the spring constant Kv in FIG. The first elastic body B73 is disposed with a gap in the axial direction so that no spring force acts on the diaphragm 6 and the stepped portion 31 of the outer yoke 3 in the axial direction.

It is desirable to set lower than the axial spring constant by the first elastic body A72 and higher than the radial spring constant by the first elastic body B73. By setting in this way, the reliability of the electrodynamic exciter when the vertical wall surface is mounted can be greatly improved, as described in the first and second embodiments.

Embodiment 4 FIG.
FIG. 8 is a partial cross-sectional view showing the configuration of the main part of the electrodynamic exciter according to the fourth embodiment of the present invention, which corresponds to FIG. 3 of the first embodiment. 8, the same reference numerals as those in FIGS. 3 and 6 denote the same or corresponding parts. The fourth embodiment is different from the second embodiment shown in FIG. 6 in that the edge of the second elastic body 8 having a substantially U-shaped cross section is carved on the outer peripheral surface of the outer yoke 3. This is a point fitted in the groove 32.

  Also in the fourth embodiment, as in the second embodiment, the vibration characteristic in the low frequency region of the electrodynamic exciter is improved by setting the spring constant in the longitudinal direction of the first elastic body 7 lower. be able to. In addition, when used in a state where the axis of the electrodynamic exciter is tilted from the gravity axis or the electrodynamic exciter is mounted on a vertical wall surface, the spring constant in the short direction of the cross section of the first elastic body 7 is increased. By setting, the magnetic circuit part composed of the inner yoke 1, the magnet 2 and the outer yoke 3 can be elastically supported with a high spring constant. For this reason, it is possible to prevent the axis of the magnetic circuit that occupies most of the total weight from tilting with respect to the axis of the electrodynamic exciter, and to prevent the occurrence of disconnection failure due to contact between the coil 5 and the outer yoke 3 or the like. Can do. Therefore, the reliability of the electrodynamic exciter when the vertical wall surface is mounted can be greatly improved.

Embodiment 5 FIG.
FIG. 9 is a partial cross-sectional view showing the configuration of the main part of the electrodynamic exciter according to the fifth embodiment of the present invention, which corresponds to FIG. 3 of the first embodiment. In FIG. 9, the same reference numerals as those in FIGS. 3, 6, and 8 denote the same or corresponding parts. The fifth embodiment is different from the second embodiment shown in FIG. 6 and the fourth embodiment shown in FIG. 8 in that the one end surface edge portion of the second elastic body 8 having a substantially U-shaped cross section is provided. The outer yoke is covered with the end surface in the axial direction of the head.

  Also in the fifth embodiment, similarly to the second and fourth embodiments, by setting the spring constant in the longitudinal direction of the cross section of the first elastic body 7 lower, the low frequency region of the electrodynamic exciter Vibration characteristics can be improved. In addition, when used in a state where the axis of the electrodynamic exciter is tilted from the gravity axis or the electrodynamic exciter is mounted on a vertical wall surface, the spring constant in the short direction of the cross section of the first elastic body 7 is increased. By setting, the magnetic circuit part composed of the inner yoke 1, the magnet 2 and the outer yoke 3 can be elastically supported with a high spring constant. For this reason, it is possible to prevent the axis of the magnetic circuit that occupies most of the total weight from tilting with respect to the axis of the electrodynamic exciter, and to prevent the occurrence of disconnection failure due to contact between the coil 5 and the outer yoke 3 or the like. Can do. Therefore, the reliability of the electrodynamic exciter when the vertical wall surface is mounted can be greatly improved.

Embodiment 6 FIG.
FIG. 10 is a perspective view showing the overall appearance of the electrodynamic exciter according to the sixth embodiment of the present invention, and corresponds to FIG. 4 of the first embodiment. 10, the same reference numerals as those in FIGS. 1 and 4 denote the same or corresponding parts. In the first to fifth embodiments, the second elastic body 8 is formed in a ring shape so as to cover the outer periphery of the outer yoke 3 and the diaphragm 6. On the other hand, in the sixth embodiment, the second elastic body 81 is not ring-shaped, but is divided and fixed at at least three locations on the outer peripheral surface of the electrodynamic exciter. In the figure, 62 is an outer peripheral wall surface of the diaphragm 6, and 81 is a second elastic body that partially elastically supports the outer yoke 3 and the diaphragm 6. The second elastic body 81 has a U-shaped cross-sectional shape and is mounted in such a manner as to sandwich the outer yoke 3 and the diaphragm 6 and is provided with a detachment prevention measure (not shown) such as adhesion.

  The cross-sectional configuration including the second elastic body 81 of the electrodynamic exciter having the external configuration shown in FIG. 10 is the same as the cross-sectional configuration shown in FIG. However, the structure in which the second elastic body 81 fixes the outer yoke 3 and the diaphragm 6 is not limited to that shown in FIG. 10, and as shown in the first to third embodiments, the outer wall surface of the outer yoke is arranged in the radial direction. A stepped portion that protrudes from the outer yoke 3 may be provided, or a groove portion may be provided on the outer peripheral surface of the outer yoke 3 shown in the fourth embodiment. The cross-sectional configuration of the first elastic body 7 may be any configuration shown in the first to fourth embodiments.

  According to the electrodynamic exciter of the sixth embodiment, as compared with the ring-shaped second elastic body 8, the divided second elastic body 81 can be significantly improved in assembling and cost can be reduced. It becomes.

Embodiment 7 FIG.
FIG. 11 is a cross-sectional view showing a configuration of an electrodynamic exciter according to Embodiment 7 of the present invention. FIG. 11A is a cross-sectional view taken along a plane perpendicular to the axis of the electrodynamic exciter, and FIG. FIG. 3 is a cross-sectional view of a plane including an axis. 11A is a cross-sectional view at the AA position shown in FIG. 11B, and FIG. 11B is a cross-sectional view at the BB position shown in FIG. 11A. 11, the same reference numerals as those in FIG. 1 denote the same or corresponding parts. In the first to fifth embodiments, the first elastic body 7 or the like is provided in a ring shape so as to surround the outer periphery of the outer yoke 3. On the other hand, in the seventh embodiment, the first elastic body 75 is not ring-shaped but is divided into a plurality of pieces in the circumferential direction. Although four divided first elastic bodies 75 are provided in FIG. 11, at least three first elastic bodies 75 may be provided.

  The shape and configuration of the first elastic body 75 in the cross section shown in FIG. 11B are the same as those in the first embodiment, but the cross sectional shape and cross section configuration of the first elastic body 75 are as shown in FIG. It is not restricted to what is shown to (B). The cross-sectional shape and cross-sectional configuration of the first elastic body 75 may be any cross-sectional shape and cross-sectional configuration shown in the first to fifth embodiments. The configuration of the second elastic body 8 may be any of the configurations shown in the first to fifth embodiments. Further, as shown in the sixth embodiment, the second elastic body may be divided. However, when the first elastic body and the second elastic body are both divided, there is no waterproof function, so that there may be a problem in outdoor use.

  Even with the electrodynamic exciter of the sixth embodiment, the axis of the magnetic circuit, which occupies most of the entire weight, can be prevented from tilting with respect to the axis of the electrodynamic exciter. It is possible to prevent the occurrence of disconnection failure due to the contact of the wire. Accordingly, the reliability of the electrodynamic exciter when the vertical wall surface is mounted can be greatly improved, and the cost can be reduced.

1: Inner yoke 2: Magnet 3: Outer yoke 5: Coil 6: Diaphragm 7, 72, 73, 75: First elastic body 8, 81: Second elastic body 61, 62: Frame portion of diaphragm

Claims (7)

A magnetic circuit unit including a bowl-shaped outer yoke, a magnet and an inner yoke disposed between the bowl-shaped outer yokes,
A coil disposed in a magnetic gap formed in the magnetic circuit section;
A diaphragm to which the coil is fixed;
In an electrodynamic exciter provided with an elastic body that elastically connects the diaphragm and the magnetic circuit unit such that the diaphragm and the magnetic circuit unit have a predetermined gap,
The elastic body is composed of at least two elastic bodies, a first elastic body and a second elastic body, and the first elastic body and the second elastic body are vibrations of the diaphragm. An electromotive exciter characterized in that the vicinity of the outer periphery of the outer yoke and the vicinity of the outer periphery of the diaphragm are connected so as to generate mutually opposing pressing forces in the axial direction.   The first elastic body is an elastic body that is sandwiched between a surface facing the outer yoke in the vicinity of the outer periphery of the diaphragm and a portion in the vicinity of the outer periphery of the outer yoke, and compressively deforms in the axial direction. The electrodynamic exciter according to claim 1.   2. The second elastic body is an elastic body that stretches and deforms in the axial direction across an outer peripheral end portion of the diaphragm and a part of an outer peripheral wall of the outer yoke. The electrodynamic exciter according to claim 2.   The said 1st elastic body or said 2nd elastic body is a ring shape surrounding the peripheral part of the said outer yoke, and the peripheral part of the said diaphragm, The Claim 2 or Claim 3 characterized by the above-mentioned. Electrodynamic exciter.   3. The first elastic body or the second elastic body is provided so as to partially elastically support at least three locations in the circumferential direction of the outer yoke and the diaphragm. Alternatively, the electrodynamic exciter according to claim 3.   The first elastic body is provided in the vicinity of the outer periphery of the diaphragm so as to be perpendicular to the surface of the diaphragm, and at least a part thereof has a frame portion facing a part of the outer peripheral wall of the outer yoke. The first elastic body is sandwiched between a frame portion of the diaphragm and an outer peripheral wall of the outer yoke, and the first elastic body is compressively deformed in a radial direction that is a direction perpendicular to the axial direction. To 5. The electrodynamic exciter according to any one of 5 to 5.   The electrodynamic exciter according to claim 6, wherein the first elastic body is set to have a higher elastic constant in the radial direction than the elastic constant in the axial direction.

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