JP2019033389A - Speaker, earphone, hearing aid, and portable terminal device - Google Patents

Abstract

To provide a speaker or the like for suppressing decrease in a magnetic fluid.SOLUTION: A speaker 1 includes a magnet 17, a plate 16 having an outer peripheral edge 16b and magnetically coupled to a first magnetic pole of a magnet 17, a yoke 18 having a cylindrical portion 18b opposed to the outer peripheral edge 16b and disposed outside the outer peripheral edge 16b and magnetically coupled to a second magnetic pole of the magnet 17, a voice coil 15 disposed in a magnetic gap 23 between the outer peripheral edge 16b and the cylindrical portion 18b, a magnetic fluid 30 disposed at least between the voice coil 15 and the outer peripheral edge 16b, and a first adhesive portion 41 bonding the plate 16 and the magnet 17. The first adhesive portion 41 includes a first portion 41a in which a first adhesive is cured in a gap between bonding surfaces of the plate 16 and the magnet 17 and a second portion 41b in which the first adhesive is cured outside the gap, and the second portion 41b covers the outlet of the gap in a direction different from the direction toward the magnetic fluid 30.SELECTED DRAWING: Figure 5

Description

  The present disclosure relates to a speaker, an earphone, a hearing aid, and a portable terminal device.

  In order to improve the sound quality of a speaker, a technique in which a magnetic fluid is arranged in a magnetic circuit has been proposed. For example, a speaker disclosed in Patent Document 1 includes a magnet, a yoke and a plate connected to the magnet, and a voice coil disposed in a magnetic gap between the yoke and the plate. The voice coil is joined to the diaphragm. Further, the speaker includes a magnetic fluid between the plate and the voice coil. The ferrofluid supports the voice coil against the plate.

Japanese Patent No. 6021023

  In the loudspeaker disclosed in Patent Document 1, magnetic fluid may enter a gap between members such as between a plate and a magnet and leak out of the gap due to capillary action. As a result, the amount of the magnetic fluid that supports the voice coil is reduced, so that the function of supporting the voice coil in the magnetic fluid is lowered, and an abnormality may occur in the speaker.

  The present disclosure provides a speaker, an earphone, a hearing aid, and a portable terminal device that suppress a decrease in magnetic fluid.

  A speaker according to one non-limiting exemplary embodiment of the present disclosure includes a magnet, a first member that has a first facing portion, and is magnetically coupled to a first magnetic pole of the magnet, and the first facing. A second member having a second opposing portion disposed opposite to the first opposing portion and magnetically coupled to a second magnetic pole opposite to the first magnetic pole of the magnet And a voice coil disposed in a magnetic gap formed between the first facing portion and the second facing portion, and a magnetic fluid disposed at least between the voice coil and the first facing portion, A first adhesive portion that adhesively bonds the first member and the magnet, and the first adhesive portion is cured by the first adhesive within a gap between the first member and the magnet. A first portion that has been cured, and a first portion where the first adhesive is cured outside the gap. And a portion, said second portion is formed to cover the outlet of the gap orientation different from the direction toward the magnetic fluid.

  An earphone according to one non-limiting exemplary aspect of the present disclosure includes the speaker.

  A hearing aid according to a non-limiting exemplary aspect of the present disclosure includes the speaker.

  A portable terminal device according to one non-limiting exemplary embodiment of the present disclosure includes the speaker.

  According to the technique of the present disclosure, it is possible to suppress a decrease in magnetic fluid.

FIG. 1 is a schematic perspective view showing the appearance of a speaker according to an embodiment. FIG. 2 is a schematic exploded perspective view of the speaker of FIG. 3 is a schematic cross-sectional view of a cross section passing through the axis of the speaker of FIG. FIG. 4 is an enlarged view showing a joint portion of the stopper, the plate, and the magnet in the speaker of FIG. 3 in a state where no adhesive portion is formed. FIG. 5 is an enlarged view showing a joint portion of the stopper, plate, and magnet in the speaker of FIG. 3 with an adhesive portion formed. FIG. 6 is a schematic perspective view showing an example of an earphone to which the speaker according to the embodiment is applied. FIG. 7 is a schematic exploded perspective view of the earphone of FIG. FIG. 8 is a schematic diagram illustrating an example of a hearing aid to which the speaker according to the embodiment is applied. FIG. 9 is a schematic diagram illustrating an example of a portable terminal device to which the speaker according to the embodiment is applied.

  In the speaker described in Patent Document 1 cited in “Background Art”, the magnetic fluid is disposed on the edge of the plate. Furthermore, the edge of this plate is located in the vicinity of the joint surface between the plate and the magnet. When the voice coil vibrates when the sound wave is generated, the magnetic fluid also vibrates, and thereby the magnetic fluid contacts the joint surface. At this time, a capillary phenomenon may occur in the magnetic fluid due to the surface tension of the magnetic fluid, and the magnetic fluid may enter the gap between the joint surfaces. The infiltrated magnetic fluid leaks from, for example, an outlet of a gap located on the opposite side of the magnetic fluid. Thereby, the magnetic fluid in a magnetic space | gap reduces and the function of a magnetic fluid falls. Accordingly, the present inventors have devised the following technique in order to suppress the decrease in magnetic fluid as described above.

  A speaker according to an aspect of the present disclosure includes a magnet, a first facing portion, a first member magnetically coupled to the first magnetic pole of the magnet, the first facing portion facing the first member, and the first facing portion. A second member having a second facing portion disposed outside the one facing portion and magnetically coupled to a second magnetic pole opposite to the first magnetic pole of the magnet; and the first facing portion And a voice coil disposed in a magnetic gap formed between the second facing portions, a magnetic fluid disposed at least between the voice coil and the first facing portion, the first member, and the magnet A first adhesive portion that is adhesively bonded, and the first adhesive portion includes a first portion in which the first adhesive is cured within a gap between the first member and the magnet, and the gap. A second portion of the first adhesive hardened outside the front, The second portion is formed to cover the outlet of the gap orientation different from the direction toward the magnetic fluid.

  According to the said aspect, the 2nd part of a 1st adhesive agent part covers the exit of the gap | interval of the joining surface of a 1st member and a magnet. For this reason, even if it is a case where magnetic fluid penetrate | invades into the said gap | interval, a 2nd part suppresses that magnetic fluid leaks from the said exit of a gap | interval. Therefore, a decrease in magnetic fluid can be suppressed.

  In the speaker according to one aspect of the present disclosure, the second portion is located at a corner formed by the surface of the first member and the surface of the magnet, and the corner is adjacent to the outlet of the gap. Good. According to the above aspect, the second part of the first adhesive part closes the outlet of the gap adjacent to the first member and the corner of the magnet. The second part located at the corner can effectively close and seal the exit of the gap.

  A speaker according to an aspect of the present disclosure includes a third member that is bonded to the first member and the magnet, a second adhesive portion that adhesively bonds the first member, the magnet, and the third member. The third member may be disposed to cover the outlet of the gap and the second portion. According to the above aspect, the third member covers the outlet of the gap and the second portion of the first adhesive portion, and is adhesively bonded to the first member and the magnet. Leakage can be suppressed.

  In the speaker according to an aspect of the present disclosure, the second adhesive portion may cover the entire second portion. According to the above aspect, the second adhesive portion can suppress leakage of the magnetic fluid through the second portion of the first adhesive portion.

  In the speaker according to an aspect of the present disclosure, the third member may form a space for accommodating the second portion together with the first member and the magnet. According to the said aspect, the 2nd part of a 1st adhesive agent part can be formed in the lump shape according to the shape of the said space. Therefore, the second portion can cover and seal the entire outlet of the gap with a sufficient thickness.

  In the speaker according to one aspect of the present disclosure, the first member has a corner at an end portion distal to the gap outlet on a surface adjacent to the gap outlet, and the third member includes the first member. It may have a shape that fits into the corner of one member, and the second adhesive portion may extend across the corner of the first member. According to the said aspect, a 2nd adhesive agent part extends across the corner | angular part of a 1st member. For this reason, even when the magnetic fluid has entered the gap between the first member and the third member, it is difficult for the magnetic fluid to advance at the corners. Therefore, the progress of the penetration of the magnetic fluid is suppressed.

  In the speaker according to one aspect of the present disclosure, the second adhesive constituting the second adhesive portion may be a visible light curable adhesive, and the third member may have a light-transmitting property. According to the above aspect, the second adhesive can be reliably and rapidly cured.

  In the speaker according to one aspect of the present disclosure, the second adhesive constituting the second adhesive portion may include a fluorescent agent. According to the said aspect, the adhesion state of a 2nd adhesive agent can be confirmed by projecting the light which makes a fluorescent agent light-emit on the 2nd adhesive agent after joining of a member. Therefore, it is possible to form a favorable second adhesive part.

  An earphone according to an aspect of the present disclosure includes the speaker. According to the above aspect, the same effect as the speaker according to one aspect of the present disclosure can be obtained.

  A hearing aid according to an aspect of the present disclosure includes the speaker. According to the above aspect, the same effect as the speaker according to one aspect of the present disclosure can be obtained.

  According to one aspect of the present disclosure, a portable terminal device includes the speaker. According to the above aspect, the same effect as the speaker according to one aspect of the present disclosure can be obtained.

  Hereinafter, the speaker 1 and the like according to the embodiment of the present disclosure will be specifically described with reference to the drawings. It should be noted that each of the embodiments described below shows a comprehensive or specific example. Numerical values, shapes, components, arrangement positions and connection forms of components, steps (steps), order of steps, and the like shown in the following embodiments are merely examples, and are not intended to limit the present disclosure. In addition, among the constituent elements in the following embodiments, constituent elements that are not described in the independent claims indicating the highest concept are described as optional constituent elements. In the following description of the embodiments, expressions with “substantially” such as substantially parallel and substantially orthogonal may be used. For example, “substantially parallel” not only means completely parallel, but also means substantially parallel, that is, including a difference of, for example, several percent. The same applies to expressions involving other “abbreviations”. Each figure is a mimetic diagram and is not necessarily illustrated strictly. Furthermore, in each figure, the same code | symbol is attached | subjected to the substantially same component, and the overlapping description may be abbreviate | omitted or simplified.

[Embodiment]
[1. Speaker]
Hereinafter, the speaker 1 according to the embodiment will be described. Referring to FIG. 1, the external appearance of a speaker 1 according to an embodiment is schematically shown in a perspective view. As shown in FIG. 1, the speaker 1 includes a casing 14 and a diaphragm 10 attached to the casing 14, and emits sound by vibrating the diaphragm 10. In the present embodiment, the external shape of the speaker 1 is a cylindrical shape, but is not limited to this, and may be any shape.

  Referring to FIG. 2, an exploded perspective view of the speaker 1 is schematically shown. Further, referring to FIG. 3, there is schematically shown a sectional view of a section passing through the axis of the cylindrical speaker 1 of FIG. As shown in FIG. 2, the speaker 1 includes a diaphragm 10, a stopper 13, a housing 14, a voice coil 15, a plate 16, a magnet 17, a yoke 18, a spacer 19, and a base terminal 20. And a dust-proof net 21.

  As shown in FIGS. 2 and 3, the diaphragm 10 has a thin disk shape. The diaphragm 10 includes a central disk-shaped diaphragm body 11 and an annular or ring-shaped diaphragm edge 12 surrounding the outer periphery of the diaphragm body 11. The diaphragm edge 12 is flexible, and the diaphragm body 11 is more rigid than the diaphragm edge 12. The outer peripheral edge of the diaphragm body 11 and the inner peripheral edge of the diaphragm edge 12 are coupled to each other, and the diaphragm body 11 and the diaphragm edge 12 are integrated. The outer peripheral edge of the diaphragm edge 12 is fixed to the housing 14. The diaphragm body 11 is coupled to the voice coil 15 in the vicinity of the outer peripheral edge thereof. As a result, when the voice coil 15 vibrates, the diaphragm body 12 and the diaphragm edge 12 vibrate together while the diaphragm edge 12 is deformed.

  The housing 14 has a cylindrical shape. Inside the housing 14, a stopper 13, a voice coil 15, a plate 16, a magnet 17, a yoke 18, a spacer 19, a base terminal 20 and a dustproof net 21 are arranged. The diaphragm 10 is disposed at one end of the housing 14 in the axial direction, and the base terminal 20 is disposed at the other end. A spacer 19, a yoke 18, a magnet 17, a plate 16, and a stopper 13 are stacked in this order from the base terminal 20 toward the diaphragm 10, and are joined to each other.

  The base terminal 20 converts a sound electrical signal supplied from the outside of the speaker 1 and supplies it to the voice coil 15. The base terminal 20 has an annular plate shape having a through hole in the center. The base terminal 20 includes an electric circuit and terminals not shown. The terminal of the base terminal 20 is electrically connected to the outside of the speaker 1.

  The spacer 19 is disposed between the base terminal 20 and the yoke 18 and separates them from each other. The spacer 19 has an annular plate shape having a through hole in the center. The spacer 19 may be omitted.

  The yoke 18 is made of a magnetic material. The yoke 18 has a bottomed cylindrical shape, and has an annular plate-shaped bottom portion 18a and a cylindrical tube portion 18b. The bottom 18a has a through hole in the center. The yoke 18 is disposed with the bottom 18 a in contact with the spacer 19. Here, the yoke 18 is an example of a second member.

  The magnet 17 is a member having two magnetic poles that are counter electrodes. An example of the magnet 17 is a permanent magnet. The magnet 17 has a through hole 17a at the center and has a cylindrical shape, for example, a donut shape. The magnet 17 is disposed coaxially with the yoke 18 inside the cylindrical portion 18 b of the yoke 18. The magnet 17 is disposed with one annular end surface 17b in the axial direction in contact with the bottom 18a of the yoke 18. The magnet 17 does not contact the cylindrical portion 18b of the yoke 18, and a cylindrical space 22 is formed between the outer peripheral surface of the magnet 17 and the cylindrical portion 18b. Such a magnet 17 is physically connected to the yoke 18. Further, the second magnetic pole, which is one of the two magnetic poles of the magnet 17, is magnetically coupled to the yoke 18.

  The plate 16 is made of a magnetic material. The plate 16 is disposed on the other annular end surface 17 c in the axial direction of the magnet 17. The plate 16 is physically connected to the magnet 17. Further, the plate 16 is magnetically coupled to the first magnetic pole opposite to the second magnetic pole, which is the other of the two magnetic poles of the magnet 17. The plate 16 has a through-hole 16a in the center and has an annular plate shape. The plate 16 is arranged coaxially with the magnet 17. The outer diameter of the outer peripheral edge 16 b of the plate 16 is equal to the outer diameter of the magnet 17. For this reason, the outer peripheral edge 16 b is substantially flush with the outer peripheral surface of the magnet 17. Note that the outer diameter of the outer peripheral edge 16 b may be larger than the outer diameter of the magnet 17. Further, the inner diameter of the through hole 16 a of the plate 16 is larger than the inner diameter of the through hole 17 a of the magnet 17. Therefore, a part of the end surface 17 c of the magnet 17 is exposed without being covered with the plate 16 in the through hole 16 a. Here, the plate 16 is an example of a first member.

  The plate 16 is disposed inside the cylindrical portion 18 b of the yoke 18. The outer peripheral edge 16 b of the plate 16 faces the inner peripheral surface of the cylindrical portion 18 b of the yoke 18. In other words, the cylindrical portion 18b is disposed outside the outer peripheral edge 16b of the plate 16, specifically, is disposed radially outward of the outer peripheral edge 16b and faces the outer peripheral edge 16b. A gap 23 is formed between the outer peripheral edge 16b and the inner peripheral surface of the cylindrical portion 18b. The first magnetic pole, which is one magnetic pole of the magnet 17, forms a magnetic field at the outer peripheral edge 16 b of the plate 16, and the second magnetic pole, which is the counter magnetic pole of the magnet 17, forms a magnetic field at the cylindrical portion 18 b of the yoke 18. To do. Thereby, a magnetic field directed from one to the other is formed between the outer peripheral edge 16b and the inner peripheral surface of the cylindrical portion 18b. Therefore, the air gap 23 forms a magnetic air gap. Here, the outer peripheral edge 16b of the plate 16 is an example of a first facing portion, and the cylindrical portion 18b of the yoke 18 is an example of a second facing portion.

  The plate 16, the magnet 17, and the yoke 18 as described above form a magnetic circuit in which magnetic flux circulates. In the magnetic circuit, a magnetic flux that circulates through the magnet 17, the plate 16, the magnetic gap 23, the yoke 18, and the magnet 17 in this order or in the reverse order is formed.

  The stopper 13 fixes the plate 16 to the magnet 17. By providing the stopper 13, the volume of the space 25 between the plate 16 and the diaphragm body 11 is reduced. Since the volume of the space 25 is related to the sound quality of the speaker 1, the stopper 13 is also provided to adjust the volume of the space 25. The stopper 13 is disposed so as to cover a part of the plate 16 and an exposed portion of the end surface 17 c of the magnet 17. The stopper 13, the plate 16 and the magnet 17 are adhesively bonded to each other. Details of adhesive bonding will be described later. The stopper 13 is made of a nonmagnetic material, for example, made of resin. Moreover, the stopper 13 is comprised so that the light of visible region can be permeate | transmitted, for example, is produced in translucent or transparent. Examples of the constituent material of the stopper 13 include polycarbonate (also referred to as “PC”), polyether ether ketone (also referred to as “PEEK”), and the like. However, the constituent material of the stopper 13 may be any material that can transmit light in the visible light range and is resistant to the magnetic fluid 30 described later. Specifically, the constituent material of the stopper 13 may be a material having resistance to the base liquid constituting the magnetic fluid 30. When the fats and oils shown in the following Table 1 are used for the base liquid, materials having resistance to the respective fats and oils as shown in Table 1 may be applied to the constituent material of the stopper 13. Here, the stopper 13 is an example of a third member.

  The voice coil 15 includes a coil portion 15a made of a wire wound in a cylindrical shape, and a wire end portion 15b extending from the coil portion 15a. The coil portion 15a is disposed in the magnetic gap 23 and surrounds the outer peripheral edge 16b of the plate 16 from the outside. The coil portion 15 a is disposed at a distance from the plate 16 and the yoke 18, and is disposed coaxially with the plate 16 and the yoke 18. Thereby, the axial center direction of the coil part 15a, the axial center direction of the through-hole 16a of the plate 16, and the axial center direction of the cylinder part 18b of the yoke 18 are substantially parallel. Further, the coil portion 15 a is joined to the diaphragm body 11 of the diaphragm 10. Further, the end portion 15 b is electrically connected to the base terminal 20.

  The extending direction of the wire in the coil portion 15 a, that is, the circumferential direction of the coil portion 15 a is substantially perpendicular to the direction of the magnetic field between the plate 16 and the yoke 18 in the magnetic gap 23. For this reason, when an electrical signal is input to the voice coil 15, the coil portion 15a vibrates in the axial direction by the action of the magnetic field in the magnetic gap 23. That is, the coil portion 15 a reciprocates in the direction toward the diaphragm 10 and the base terminal 20. When the coil portion 15a vibrates, the diaphragm 10 vibrates. The vibration plate 10 vibrates to cause a pressure change in the air on the outer surface and the inner surface of the vibration plate 10, thereby generating sound waves. Specifically, the diaphragm 10 radiates sound waves from the opened outer surface. The outer surface of the diaphragm 10 is an outer surface of the housing 14, and the inner surface of the diaphragm 10 is an inner surface of the housing 14.

  As described above, the stopper 13, the plate 16, the magnet 17, the yoke 18, the spacer 19, and the base terminal 20 assembled to each other have one through hole 24 that passes through them in the direction from the diaphragm 10 toward the base terminal 20. Form together. The dust-proof net 21 is attached to the base terminal 20 so as to cover the opening of the through-hole 24 and prevents foreign matter from entering the through-hole 24 from the outside.

  The speaker 1 includes a magnetic fluid 30. The magnetic fluid 30 is filled between the coil portion 15 a and the outer peripheral edge 16 b of the plate 16 in the magnetic gap 23. The magnetic fluid 30 is filled over the entire circumference of the outer peripheral edge 16b and distributed in an annular shape. The magnetic fluid 30 is a fluid containing a magnetic material. An example of the magnetic fluid 30 is composed of ferromagnetic fine particles (for example, about 10 nm in diameter) such as magnetite and manganese zinc ferrite, a surfactant that covers the surface of the ferromagnetic fine particles, and a base liquid such as water and oil. Magnetic colloid solution. Although not limited to this, in the present embodiment, the following description will be made on the assumption that hydrocarbon-based oil, that is, mineral oil, is used for the base liquid of the magnetic fluid 30. Although such a magnetic fluid 30 is a liquid, it has a property of being magnetized and attracted to a magnet.

  Such a magnetic fluid 30 is held between the coil portion 15a and the outer peripheral edge 16b by a magnetic force generated by the magnetic field in the magnetic gap 23 to form a fluid O-ring. The coil portion 15a is supported by the magnetic fluid 30 and the plate 16 by the magnetic force through the magnetic fluid 30, and thereby the position of the coil portion 15a with respect to the outer peripheral edge 16b is maintained. Further, the magnetic fluid 30 functions as a fluid O-ring, thereby blocking the space 25 on the inner surface side of the diaphragm body 11 and the cylindrical space 22. The cylindrical space 22 communicates with a space 26 on the inner surface side of the diaphragm edge 12. Thereby, the spaces 25 and 26 are blocked by the magnetic fluid 30. Therefore, it is possible to suppress the sound pressure of the speaker 1 from being lowered by the air in the space 26 on the inner surface side of the diaphragm edge 12 that generates sound waves leaking into the space 25.

  The magnetic fluid 30 has a center holding force. Therefore, even when the coil portion 15a vibrates with a large amplitude, the magnetic fluid 30 does not bring the diaphragm 10 and the voice coil 15 into contact with the plate 16 and the yoke 18 by the center holding force. , Can be vibrated stably.

  Next, details of the joint portion of the stopper 13, the plate 16, and the magnet 17 will be described. Referring to FIG. 4, the joined portion of the stopper 13, the plate 16, and the magnet 17 in the speaker 1 of FIG. 3 is shown enlarged without an adhesive portion being formed. Referring to FIG. 5, the joint portion of the stopper 13, the plate 16, and the magnet 17 in the speaker 1 of FIG. 3 is shown enlarged with an adhesive portion formed.

  As shown in FIG. 4, the annular plate 16 has two flat annular surfaces 16 c and 16 d facing in opposite directions between the through hole 16 a and the outer peripheral edge 16 b. The plate 16 is disposed so that the surface 16 d faces the end surface 17 c of the magnet 17. The stopper 13 is disposed so as to cover the plate 16 and the magnet 17 over the surface 16c, the inner peripheral surface of the through hole 16a, and the end surface 17c. The stopper 13 has a surface 13b shaped to follow the shape of the inner surface of the surface 16c and the through hole 16a, and the surface 13b fits closely to the corner formed by the surface 16c and the inner surface of the through hole 16a. . The surface 13b is annular and has a radial cross section that is recessed in an L shape. Here, the corner formed by the inner peripheral surface of the surface 16 c and the through hole 16 a is distal to the outlet of the gap on the inner peripheral surface of the through hole 16 a adjacent to the outlet of the gap between the plate 16 and the magnet 17. It is a corner | angular part in the edge part.

  An annular surface 13a facing the end surface 17c of the stopper 13 has an annular surface 13ab shaped like the end surface 17c in a part on the radially inner side, and is inclined so as to be separated from the end surface 17c in the other part on the radially outer side. The inclined annular surface 13aa is provided. The inclined annular surface 13aa is inclined with respect to the end surface 17c so as to be separated from the end surface 17c toward the radially outer side. As a result, a sealed space 27 that is an annular gap is formed between the inclined annular surface 13aa, the through hole 16a, and the end surface 17c. In this example, the sealed space 27 has a right-angled triangular radial cross section, but the radial cross-sectional shape of the sealed space 27 may be a shape that covers the outlet of the gap between the surface 16d and the end face 17c. Any shape is possible. For example, the inclined annular surface 13aa, which is a flat inclined surface, may be a bent surface or a curved surface protruding or recessed toward the outlet.

  The stopper 13, the plate 16 and the magnet 17 are joined together by an adhesive. Specifically, as shown in FIG. 5, the plate 16 is joined to the magnet 17 by a first adhesive portion 41 in which the first adhesive is cured. The stopper 13 is joined to the plate 16 and the magnet 17 by a second adhesive portion 42 in which the second adhesive is cured.

  The first adhesive portion 41 integrally includes a first portion 41a and a second portion 41b. The first part 41a and the second part 41b are not separated from each other and form a continuous adhesive part together. The first portion 41a is located in the gap between the surface 16d of the plate 16 and the end face 17c of the magnet 17, and is formed by curing the first adhesive filled in the gap. The first portion 41a joins the plate 16 to the magnet 17 and seals between the surface 16d and the end surface 17c. Here, the surface 16d and the end surface 17c are the bonding surfaces of the plate 16 and the magnet 17, respectively, and are examples of the bonding surfaces of the first member and the magnet.

  Further, the second portion 41b is located outside the gap between the surface 16d and the end surface 17c. The second portion 41b is formed by curing the first adhesive filled in the sealed space 27. The second portion 41 b seals the corner formed by the inner peripheral surface of the through hole 16 a of the plate 16 and the end surface 17 c of the magnet 17. The corners are annular and have a radial cross section that is recessed in an L shape. Such a second portion 41b covers and closes the exit of the gap between the surface 16d and the end surface 17c. Here, the exit of the gap between the surface 16 d and the end face 17 c at the corner is an example of the exit of the gap in a direction different from the direction toward the magnetic fluid 30.

  The second adhesive portion 42 is filled with a second adhesive filled between the surface 13b of the stopper 13 and the surface 16c of the plate 16 and between the surface 13b and the inner peripheral surface of the through hole 16a of the plate 16. It is formed by curing. The second adhesive portion 42 joins the stopper 13 to the magnet 17 and seals between the surface 13b and the surface 16c and between the surface 13b and the inner peripheral surface of the through hole 16a. Further, the second adhesive portion 42 is also formed by curing the second adhesive filled between the surface 13 a of the stopper 13 and the end surface 17 c of the magnet 17. The second adhesive portion 42 joins the stopper 13 to the magnet 17 and seals between the surface 13a and the end surface 17c. In the sealing space 27, the second adhesive portion 42 is formed so as to cover the second portion 41 b of the first adhesive portion 41 from above over the entire circumference of the sealing space 27. That is, the second adhesive portion 42 covers the entire second portion 41b at the corner between the inner peripheral surface of the through hole 16a and the end surface 17c. The second adhesive portion 42 seals between the second portion 41 b and the inner peripheral surface of the through hole 16 a and between the second portion 41 b and the end surface 17 c of the magnet 17.

  The first adhesive constituting the first adhesive portion 41 and the second adhesive constituting the second adhesive portion 42 preferably have resistance to the magnetic fluid 30. The first adhesive and the second adhesive may have resistance to the base liquid constituting the magnetic fluid 30. The second adhesive is preferably a visible light curable adhesive that promotes curing when receiving light in the visible light range. Furthermore, it is preferable that a 2nd adhesive agent has a fluorescent agent as a structural component. A fluorescent agent emits light when it receives light of a specific wavelength. For example, the fluorescent agent may be configured to emit light when receiving ultraviolet light having a wavelength of 315 to 400 nm (nanometers). In this case, the second adhesive portion 42 formed by the second adhesive emits light when receiving ultraviolet light using a black light or the like. The first adhesive and the second adhesive may be different adhesives or the same adhesive.

  Here, with reference to FIG.4 and FIG.5, an example of the assembly method of the plate 16 and the stopper 13 to the magnet 17 is demonstrated. First, the first adhesive before curing is applied to the surface 16d of the plate 16 (application process of the first adhesive). At this time, the first adhesive is applied over the entire annular surface 16d. Further, the plate 16 is placed at a predetermined position on the end surface 17c with the surface 16d facing the end surface 17c of the magnet 17, and pressed toward the end surface 17c. That is, the plate 16 is bonded to the magnet 17 (bonding process of the plate 16). 4 and 5, the predetermined position is a position where the outer peripheral edge 16b of the plate 16 and the outer peripheral surface of the magnet 17 are flush with each other. When the plate 16 is pressed, the first adhesive overflows into the through hole 16a of the plate 16 from the gap between the surface 16d and the end surface 17c, and accumulates at the corners of the inner peripheral surface of the end surface 17c and the through hole 16a. Then, the first adhesive in the gap between the surface 16d and the end face 17c is cured to form the first part 41a of the first adhesive part 41, and the first adhesive accumulated in the corner is cured to the first adhesive. A second portion 41b of the agent portion 41 is formed. The first part 41a and the second part 41b are continuously extended from each other to form one continuous first adhesive part 41 together.

  Next, the second adhesive before curing is applied to the surfaces 13a and 13b of the stopper 13 (application process of the second adhesive). At this time, the second adhesive is applied to the entire surfaces of the annular surfaces 13a and 13b. Further, the stopper 13 is placed on the end surface 17c and the surface 16c with the surfaces 13a and 13b facing the end surface 17c of the magnet 17 and the surface 16c of the plate 16, respectively, and is pressed toward the end surface 17c and the surface 16c. . That is, the stopper 13 is joined to the plate 16 and the magnet 17 (joining process of the stopper 13). At this time, the surface 13b of the stopper 13 is fitted to the surface 16c of the plate 16 and the corners of the through holes 16a. The joining of the stopper 13 is preferably performed before the first adhesive is cured, that is, while the first adhesive accumulated on the end surface 17c is deformable.

  As a result, the first adhesive accumulated on the end surface 17 c is deformed in accordance with the shape of the sealing space 27 and is stored in the sealing space 27. Further, the second adhesive covers the entire first adhesive in and around the sealing space 27. The entire sealing space 27 is filled with the first adhesive and the second adhesive. Thereby, the 2nd part 41b which the 1st adhesive agent hardened | cured has a triangular-shaped radial cross section, and is formed in an annular | circular shape. The second portion 41b covers and closes the entire outlet of the gap between the surface 16d and the end surface 17c with a sufficient thickness. Further, the first adhesive is pushed by the inclined annular surface 13aa of the stopper 13 at the time of joining, and is further brought into close contact with the inner peripheral surface and the end surface 17c of the through hole 16a, whereby the second portion 41b has the surface 16d and the end surface 17c. Close the exit of the gap tightly.

  The second adhesive is cured by receiving light in the visible light range that passes through the stopper 13 to form a second adhesive portion 42 (second adhesive curing process). Note that light in the visible light region may be projected onto the stopper 13 using a light or the like. Thereby, hardening of the second adhesive is promoted.

  Moreover, you may project an ultraviolet light on the stopper 13 using the apparatus which radiate | emits ultraviolet light, such as a black light, before hardening of a 2nd adhesive agent or after hardening. Thereby, the fluorescent agent of the second adhesive emits light. The light emission state is visible through the stopper 13. By visually recognizing the light emission state of the second adhesive that emits light, it is possible to confirm the adhesion state and application state of the second adhesive. For example, before the second adhesive is cured, if the second adhesive does not cover the entire first adhesive of the second portion 41b, the joining process can be performed again.

  The first adhesive portion 41 and the second adhesive portion 42 formed as described above are disposed so that the magnetic fluid 30 on the outer peripheral edge 16b of the plate 16 passes through the gap between the plate 16 and the magnet 17 to other places. Reduce leakage. For example, the surface 16d of the plate 16 and the end face 17c of the magnet 17 are not completely flat surfaces and may include distortion or warpage. Thereby, the space | interval of the surface 16d and the end surface 17c becomes non-uniform | heterogenous, and a fine space | gap may arise between the 1st adhesive agent part 41 and the surface 16d or the end surface 17c. In such a case, a capillary phenomenon may occur in the magnetic fluid 30 due to the surface tension of the liquid fluid 30, and the magnetic fluid 30 may enter the gap between the surface 16d and the end surface 17c. The magnetic fluid 30 that has entered advances toward the through hole 16a of the plate 16 by capillary action.

  At this time, since the second portion 41b of the first adhesive portion 41 in the sealing space 27 closes the outlet from the gap between the surface 16d and the end surface 17c to the through hole 16a, the magnetic fluid 30 is sealed in the sealing space 27. Leaking into the inside is suppressed.

  Further, the second adhesive portion 42 covers the entire second portion 41b in the sealing space 27 and the periphery thereof. Thereby, the second adhesive portion 42 closes the outlet to the sealing space 27 from the gap between the inner peripheral surfaces of the second portion 41b and the through hole 16a, and the sealing space from the gap between the second portion 41b and the end surface 17c. Block the exit to 27. Therefore, the magnetic fluid 30 can be prevented from leaking into the sealed space 27 through the periphery of the second portion 41b.

  In addition, the second adhesive portion 42 extends to the gap between the inner peripheral surface of the through hole 16a and the surface 13b of the stopper 13, so that the magnetic fluid 30 leaks from the sealed space 27 to the space 25. suppress. Further, the second adhesive portion 42 also extends into the gap between the surface 16 c of the plate 16 and the surface 13 b of the stopper 13. At this time, the second adhesive portion 42 bends at the corner between the surface 16c and the inner peripheral surface of the through hole 16a, and extends across the corner. Thus, even if the magnetic fluid 30 enters the gap between the inner peripheral surface of the through hole 16a and the surface 13b, it is possible to prevent the magnetic fluid 30 from leaking into the space 25. Furthermore, the second adhesive portion 42 also extends into the gap between the end surface 17 c and the annular surface 13 ab of the stopper 13, thereby preventing the magnetic fluid 30 from leaking into the through hole 24.

  Accordingly, the magnetic fluid 30 is prevented from moving and decreasing from the position between the coil portion 15a and the outer peripheral edge 16b of the plate 16, and the functional deterioration of the magnetic fluid 30 is suppressed.

[2. effect]
As described above, according to the speaker 1 according to the embodiment, the second portion 41 b of the first adhesive portion 41 covers the outlet of the gap between the joint surfaces of the plate 16 and the magnet 17. For this reason, even when the magnetic fluid 30 enters the gap, the second portion 41b prevents the magnetic fluid 30 from leaking from the outlet of the gap. Therefore, the speaker 1 suppresses the decrease of the magnetic fluid 30 from the magnetic gap 23.

  In the speaker 1 according to the embodiment, the second portion 41 b of the first adhesive portion 41 is an outlet of the gap adjacent to the corner of the plate 16 and the magnet 17 in the gap between the joint surfaces of the plate 16 and the magnet 17. Block. The second portion 41b located at the corner can effectively close and seal the exit of the gap.

  Further, in the speaker 1 according to the embodiment, the stopper 13 covers the outlet of the gap between the joint surfaces of the plate 16 and the magnet 17 and the second portion 41 b of the first adhesive portion 41 and adheres to the plate 16 and the magnet 17. Be joined. For this reason, the stopper 13 can suppress leakage of the magnetic fluid 30 through the outlet of the gap and the second portion 41b.

  Further, in the speaker 1 according to the embodiment, the second adhesive portion 42 covers the entire second portion 41b of the first adhesive portion 41, so that leakage of the magnetic fluid 30 through the second portion 41b is suppressed. Can do.

  Further, in the speaker 1 according to the embodiment, the stopper 13 forms a sealing space 27 for accommodating the second portion 41 b of the first adhesive portion 41 together with the plate 16 and the magnet 17. At this time, the second portion 41 b can be formed in a lump shape in accordance with the shape of the sealing space 27. Therefore, the second portion 41 b can cover and seal the entire outlet of the gap between the joint surfaces of the plate 16 and the magnet 17 with a sufficient thickness.

  In the speaker 1 according to the embodiment, the plate 16 has an end distal from the outlet of the gap on the inner peripheral surface of the through hole 16a of the plate 16 adjacent to the outlet of the gap between the joint surfaces of the plate 16 and the magnet 17. The corner has a corner. The stopper 13 has a shape that fits into the corner, and the second adhesive portion 42 extends across the corner of the plate 16. For this reason, even when the magnetic fluid 30 enters the gap between the plate 16 and the stopper 13, it is difficult to advance the penetration at the corner. Therefore, the progress of the penetration of the magnetic fluid 30 is suppressed.

  In the speaker 1 according to the embodiment, since the second adhesive constituting the second adhesive portion 42 is a visible light curable adhesive and the stopper 13 has translucency, the second adhesive Reliable and quick curing is possible.

  Further, in the speaker 1 according to the embodiment, since the second adhesive constituting the second adhesive portion 42 includes a fluorescent agent, the second adhesive after joining the members emits a fluorescent agent such as ultraviolet light. By projecting the light to be made, it is possible to confirm the adhesion state of the second adhesive. Therefore, it is possible to form a good second adhesive portion 42.

[3. Example of speaker application]
An application example of the speaker 1 according to the embodiment will be described. As an application example of the speaker 1 according to the embodiment, an earphone 100 as shown in FIGS. 6 and 7 can be cited. FIG. 6 is a schematic perspective view showing an example of an earphone to which the speaker 1 according to the embodiment is applied. FIG. 7 is a schematic exploded perspective view of the earphone 100 of FIG. The earphone 100 includes an ear chip 101, a port 102, a speaker 1, a box 103, a back cover 104, and a cable 105. The speaker 1 is disposed inside a port 102 and a box 103 that are assembled together, and is connected to a cable 105. The sound generated by the speaker 1 reaches the wearer's ear via the port 102 and the ear chip 101.

  Further, as an application example of the speaker 1 according to the embodiment, a hearing aid 200 as shown in FIG. FIG. 8 is a schematic diagram illustrating an example of a hearing aid to which the speaker 1 according to the embodiment is applied. The hearing aid 200 includes a receiver 201, a hearing aid main body 202, and a lead tube 203. The configuration of the receiver 201 conforms to the configuration of the ear chip 101, the port 102, and the speaker 1 of the earphone 100.

  Further, as an application example of the speaker 1 according to the embodiment, there is a portable terminal device 300 as shown in FIG. FIG. 9 is a schematic diagram illustrating an example of a portable terminal device to which the speaker 1 according to the embodiment is applied. The speaker 1 is applied to the external speaker 301 of the portable terminal device 300 shown in FIG. The portable terminal device 300 is a smartphone in the example illustrated in FIG. 9, but may be any portable terminal device such as a mobile phone, a tablet terminal, or a smart watch.

  Moreover, the speaker 1 which concerns on embodiment may be applied to any apparatuses provided with speakers other than the apparatus mentioned above.

[4. Others]
As described above, the above embodiment has been described as an example of the technique in the present disclosure. However, the technology in the present disclosure is not limited to the above, and can be applied to embodiments in which changes, substitutions, additions, omissions, and the like are appropriately performed. Moreover, it is also possible to combine each component demonstrated by the said embodiment and the following modification, and can also be set as a new embodiment. Thus, hereinafter, modifications of the embodiment will be exemplified.

  In the speaker 1 according to the above embodiment, the first adhesive portion 41 has the second portion 41 b at a position opposite to the position of the magnetic fluid 30 with respect to the gap between the plate 16 and the magnet 17. However, the position of the second portion 41b is not limited to this. The second portion 41b may be formed at a position on the magnetic fluid 30 side, or may be formed at a position other than these. The second portion 41 b may be formed at a position where the magnetic fluid 30 can be prevented from entering the gap between the plate 16 and the magnet 17 or leakage of the magnetic fluid 30 that has entered the gap. Further, when there is a gap between the members other than the gap between the plate 16 and the magnet 17 in the vicinity of the magnetic fluid 30, the adhesive part of the gap also has the second part 41 b similar to the first adhesive part 41. You may have. Thus, the configuration of the first adhesive portion 41 can be applied to various gaps.

  In the speaker 1 according to the above embodiment, the magnetic fluid 30 is disposed between the coil portion 15a of the voice coil 15 and the outer peripheral edge 16b of the plate 16, but is not limited thereto. The magnetic fluid 30 may be disposed in a space between the coil portion 15a and the cylindrical portion 18b of the yoke 18 in addition to the space between the coil portion 15a and the outer peripheral edge 16b. Further, the magnetic fluid 30 may be disposed from the outer peripheral edge 16 b of the plate 16 to the outer peripheral surface of the magnet 17.

  As described above, the technology of the present disclosure is useful for a speaker and a device including the speaker.

1 Speaker 13 Stopper (third member)
15 Voice coil 16 Plate (first member)
16a Through-hole 16b Outer peripheral edge (first facing portion)
17 Magnet 17c End face 18 Yoke (second member)
18b Tube part (second facing part)
23 Magnetic gap 27 Sealing space 30 Magnetic fluid 41 First adhesive portion 41a First portion 41b Second portion 42 Second adhesive portion 100 Earphone 200 Hearing aid 300 Portable terminal device

Claims (11)

Magnets,
A first member having a first facing portion and magnetically coupled to the first magnetic pole of the magnet;
A second opposing portion disposed opposite to the first opposing portion and disposed outside the first opposing portion, and magnetically coupled to a second magnetic pole opposite to the first magnetic pole of the magnet; A second member,
A voice coil disposed in a magnetic gap formed between the first facing portion and the second facing portion;
A magnetic fluid disposed at least between the voice coil and the first facing portion;
A first adhesive portion that adhesively bonds the first member and the magnet,
The first adhesive portion includes a first portion in which the first adhesive is cured within a gap between the first member and the magnet, and a second portion in which the first adhesive is cured outside the gap. Including
The second portion is formed so as to cover an outlet of the gap in a direction different from a direction toward the magnetic fluid. The second part is located at a corner formed by the surface of the first member and the surface of the magnet,
The speaker according to claim 1, wherein the corner is adjacent to an outlet of the gap. A third member joined to the first member and the magnet;
A second adhesive part that adhesively bonds the first member and the magnet and the third member;
The speaker according to claim 1, wherein the third member is disposed so as to cover an outlet of the gap and the second portion. The speaker according to claim 3, wherein the second adhesive portion covers the entire second portion. The speaker according to claim 3 or 4, wherein the third member forms a space for housing the second portion together with the first member and the magnet. The first member has a corner at an end distal from the gap outlet on a surface adjacent to the gap outlet;
The third member has a shape that fits into the corner of the first member,
The speaker according to any one of claims 3 to 5, wherein the second adhesive portion extends across the corner of the first member. The second adhesive constituting the second adhesive part is a visible light curable adhesive,
The speaker according to any one of claims 3 to 6, wherein the third member has translucency. The speaker according to any one of claims 3 to 7, wherein the second adhesive constituting the second adhesive portion includes a fluorescent agent.   An earphone comprising the speaker according to claim 1.   A hearing aid comprising the speaker according to any one of claims 1 to 8.   A portable terminal device comprising the speaker according to claim 1.

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