Speaker

Abstract

A speaker 10 includes a first vibration part 20, a second vibration part 30, a magnetic circuit 40, and a frame 50. The magnetic circuit 40 includes a first magnetic gap G1 and a second magnetic gap G2. The first magnetic gap G1 is opened upward, and the second magnetic gap G2 is opened upward. A second elastic support part 37 includes an upper elastic body 38a and a lower elastic body 38b. The second vibration part 30 includes a second coupler 39 that connects a second bobbin 31 and the upper elastic body 38a and connects the second bobbin 31 and the lower elastic body 38b.

Description

Speaker

[0001] The present disclosure relates to a speaker.

[0002] The speaker disclosed in Patent Document 1 includes a second vibrating portion in addition to a first vibrating portion for emitting sound.

[0003] International Publication No. 2023 / 090124

[0004] An object of the present disclosure is to provide a speaker that includes a first vibrating portion and a second vibrating portion and that is small in size in the axial direction.

[0005] A speaker according to a first aspect is a speaker comprising a first vibration section, a second vibration section, a magnetic circuit, and a frame supporting the first vibration section, the second vibration section, and the magnetic circuit, wherein the first vibration section comprises a first coil, a first bobbin on which the first coil is provided, and a first elastic support section that elastically supports the first bobbin so as to be displaceable in the axial direction, the second vibration section comprises a second coil having a diameter larger than that of the first coil, a second bobbin on which the second coil is provided, and a second elastic support section that elastically supports the second bobbin so as to be displaceable in the axial direction, the magnetic circuit comprises a first magnetic gap in which the first coil is disposed, and a second magnetic gap in which the second coil is disposed, the first magnetic gap is open upward and the second magnetic gap is open upward, and the second elastic support section comprises an upper elastic body, a lower elastic body provided below the upper elastic body, and a second coupler that connects the second bobbin to the upper elastic body and also connects the second bobbin to the lower elastic body.

[0006] In this aspect, the speaker includes a first vibration section, a second vibration section, a magnetic circuit, and a frame. The frame supports the first vibration section, the second vibration section, and the magnetic circuit. The first vibration section includes a first coil, a first bobbin on which the first coil is provided, and a first elastic support section that elastically supports the first bobbin so that it can be displaced in the axial direction. The second vibration section includes a second coil having a diameter larger than that of the first coil, a second bobbin on which the second coil is provided, and a second elastic support section that elastically supports the second bobbin so that it can be displaced in the axial direction. The magnetic circuit includes a first magnetic gap in which the first coil is disposed, and a second magnetic gap in which the second coil is disposed. The first magnetic gap is open on the upper side, and the second magnetic gap is open on the upper side.

[0007] In this aspect, the second elastic support portion includes an upper elastic body and a lower elastic body, which allows the second vibrating portion to vibrate in a stable position.

[0008] However, when the second elastic support portion includes an upper elastic body and a lower elastic body, and the upper elastic body and the lower elastic body are each joined to the second bobbin, it is necessary to elongate the portion of the second bobbin that is located outside the magnetic circuit in the axial direction. This results in an increase in the axial size of the second vibrating portion, thereby increasing the size of the entire speaker. Therefore, in this aspect, the second vibrating portion further includes a second coupler that connects the second bobbin and the upper elastic body and also connects the second bobbin and the lower elastic body. Therefore, the upper elastic body and the lower elastic body are connected to the second bobbin via the second coupler. Therefore, it is not necessary to elongate the portion of the second bobbin that is located outside the magnetic circuit in the axial direction, thereby enabling the speaker to be made smaller in size in the axial direction.

[0009] As described above, according to this aspect, a speaker that is small in size in the axial direction can be realized.

[0010] In the embodiment described below, the first vibrating section is a vibrating section for emitting sound, and the second vibrating section is a vibrating section for canceling out vibration of the entire speaker caused by the first vibrating section. However, the first vibrating section and the second vibrating section in this embodiment are not limited to these vibrating sections. For example, both the first vibrating section and the second vibrating section may be vibrating sections for emitting sound. Alternatively, the second vibrating section may be a vibrating section for emitting sound, and the first vibrating section may be a vibrating section for canceling out vibration of the entire speaker caused by the second vibrating section.

[0011] A speaker according to a second aspect is the speaker of the first aspect, wherein at least a portion of the lower elastic body is positioned below an upper end of the second coil.

[0012] In this aspect, at least a portion of the lower elastic body is located below the upper end of the second coil, so that the space radially outward of the magnetic circuit and below the upper end of the second magnetic gap can be effectively used as a space for arranging the lower elastic body.

[0013] In the embodiment described below, the entire lower elastic body is located below the upper end of the second coil. However, this aspect is not limited to this. For example, the inner joint portion and the outer joint portion of the lower elastic body may be located below the upper end of the second coil, and the lower elastic body may have a portion that is not located below the upper end of the second coil.

[0014] A speaker according to a third aspect is the speaker according to the first or second aspect, wherein an air hole is formed in the second coupler between a connection position of the upper elastic body and a connection position of the lower elastic body.

[0015] In this aspect, the second coupler has an air vent formed between the connection position of the upper elastic body and the connection position of the lower elastic body, which makes it possible to prevent the vibration of the second vibrating part from being hindered by the influence of air resistance.

[0016] A speaker according to a fourth aspect is any one of the first to third aspects, wherein the first elastic support portion has a recess for avoiding interference with the second bobbin.

[0017] In this aspect, the first elastic support portion has a recess for avoiding interference with the second bobbin, which allows the first vibrating portion and the second vibrating portion to be closer to each other in the axial direction, making it easier to reduce the size of the speaker in the axial direction.

[0018] A speaker according to a fifth aspect is any one of the first to fourth aspects, wherein the first elastic support portion comprises an elastic body and a first coupler that connects the elastic body and the first bobbin, and the first coupler has a recess for avoiding interference with the second bobbin.

[0019] In this aspect, the first elastic support member includes an elastic body and a first coupler that connects the elastic body to the first bobbin. The first coupler has a recess that prevents interference with the second bobbin. Therefore, the recess can be formed to be less likely to deform than in an aspect in which the elastic body has a recess.

[0020] A sixth aspect of the present invention is a speaker according to the fifth aspect, wherein the first vibrating portion includes a diaphragm, and the diaphragm is connected to the first bobbin without the first coupler.

[0021] In this embodiment, the first vibrating section includes a diaphragm. The diaphragm is connected to the first bobbin without the first coupler. Therefore, compared to an embodiment in which the diaphragm is connected to the first bobbin via the first coupler, the vibration of the first bobbin can be transmitted to the diaphragm more directly.

[0022] According to the present disclosure, a speaker that is small in size in the axial direction can be realized.

[0023] Fig. 1 is a cross-sectional view of a speaker according to an embodiment; Fig. 2 is an enlarged cross-sectional view of a speaker according to an embodiment; Fig. 3 is a cross-sectional view of a magnetic circuit according to an embodiment; Fig. 4 is a cross-sectional view of a speaker according to a first modified example; Fig. 5 is a cross-sectional view of a speaker according to a second modified example;

[0024] First, an embodiment of a speaker according to the present disclosure will be described with reference to FIGS. 1 to 3. FIG.

[0025] FIG. 1 is a cross-sectional view of a speaker 10 according to this embodiment, taken along a plane passing through a central axis AX.

[0026] The speaker 10 is mounted, for example, on a side door of an automobile.

[0027] The speaker 10 has a structure that is symmetrical about a central axis AX in its main portion.

[0028] In the following description, the direction parallel to the central axis AX is referred to as the axial direction, one axial side is referred to as the upper side, and the other axial side is referred to as the lower side. The direction perpendicular to the central axis AX is referred to as the radial direction, with the radial side closer to the central axis AX being referred to as the radially inner side and the radial side farther from the central axis AX being referred to as the radially outer side.

[0029] The speaker 10 has a first vibrating part 20 that vibrates to produce sound, a second vibrating part 30 that vibrates to cancel out the vibration of the entire speaker 10 caused by the first vibrating part 20, a magnetic circuit 40, and a frame 50 that supports these.

[0030] (First Vibrating Section 20 ) The first vibrating section 20 includes a first bobbin 21 , a first coil 22 , a diaphragm 24 , an edge 25 , a cap 26 , and a first elastic support section 27 .

[0031] The first bobbin 21 has a cylindrical shape. The first coil 22 is formed on the outer peripheral surface of the lower end of the first bobbin 21.

[0032] The diaphragm 24 is a member that radiates sound by vibrating. The diaphragm 24 has a circular hole in the center and has a shape that extends radially outward and upward from the inner edge that forms the circular hole. The inner edge of the diaphragm 24 is bonded to the outer peripheral surface of the first bobbin 21. The outer edge of the diaphragm 24 is connected to the frame 50 via an edge 25. The edge 25 is made of rubber. The inner edge of the edge 25 is bonded to the outer edge of the diaphragm 24, and the outer edge of the edge 25 is bonded to the frame 50.

[0033] The cap 26 is a member that vibrates to radiate sound. The cap 26 covers the first bobbin 21 from above. The outer edge of the cap 26 is bonded to the upper surface of the diaphragm 24.

[0034] The first elastic support portion 27 elastically supports the first bobbin 21 so as to be displaceable in the axial direction. The first elastic support portion 27 is provided radially outward of the first bobbin 21. The first elastic support portion 27 is composed of a single elastic body 27a. The elastic body 27a is an annular disk-shaped elastic body having a circular hole in the center and extending radially outward from the inner edge portion that forms the circular hole. The elastic body 27a is composed of cloth. The inner edge portion of the elastic body 27a is joined to the outer peripheral surface of the first bobbin 21, and the outer edge portion of the elastic body 27a is joined to the frame 50.

[0035] 2, the elastic body 27a has an inner edge portion 27a1 joined to the outer peripheral surface of the first bobbin 21, a wavy portion 27a2 having a plurality of wavy shapes arranged in the radial direction, and an outer edge portion 27a3 joined to the frame 50. The term "plural wavy shapes" as used here means a shape in which wavy shapes that are convex upward and wavy shapes that are convex downward are alternately repeated along the radial direction.

[0036] The wavy portion 27a2 has a general portion 27a21 and a recessed portion 27a22.

[0037] The general portion 27a21 has a plurality of wave shapes arranged in the radial direction. The upper ends of the upwardly convex wave shapes of the general portion 27a21 are all located at approximately the same height, and the lower ends of the downwardly convex wave shapes of the general portion 27a21 are all located at approximately the same height.

[0038] On the other hand, the recess 27a22 has only one wave shape that is convex upward, and its upper end is located higher than the upper end of the wave shape that is convex upward of the general portion 27a21. The upper end of the second bobbin 31 is located directly below the recess 27a22. Therefore, the recess 27a22 functions to avoid interference with the second bobbin 31 when the second bobbin 31 is displaced upward.

[0039] (Second Vibrating Part 30 ) The second vibrating part 30 has a second bobbin 31 , a second coil 32 and a second elastic support part 37 .

[0040] The second bobbin 31 has a cylindrical shape. The second bobbin 31 has a larger diameter than the first bobbin 21. The second coil 32 is formed on the outer peripheral surface of the lower end of the second bobbin 31. In the inactive state (the state in which the speaker 10 is not operating) shown in FIG. 1 , the upper end of the second bobbin 31 is located above the upper end of the first coil 22.

[0041] The second elastic support portion 37 elastically supports the second bobbin 31 so as to be displaceable in the axial direction. The second elastic support portion 37 is provided on the radially outer side of the second bobbin 31.

[0042] The second elastic support portion 37 includes an upper elastic body 38 a , a lower elastic body 38 b , and a second coupler 39 .

[0043] The upper elastic body 38a and the lower elastic body 38b are provided with an axial gap between them. The lower elastic body 38b is provided below the upper elastic body 38a. The upper elastic body 38a and the lower elastic body 38b are both annular, disk-shaped elastic bodies having a circular hole in the center and extending radially outward from the inner edge forming the circular hole. The inner edges of the upper elastic body 38a and the lower elastic body 38b are joined to a second coupler 39. The second coupler 39 is joined to the outer peripheral surface of the second bobbin 31. As a result, the second coupler 39 connects the second bobbin 31 and the upper elastic body 38a, and also connects the second bobbin 31 and the lower elastic body 38b.

[0044] The upper elastic body 38a is made of cloth. As shown in Fig. 2, the upper elastic body 38a has an inner edge portion 38a1 joined to the second coupler 39, a wavy portion 38a2 having a plurality of wavy shapes arranged in the radial direction, and an outer edge portion 38a3.

[0045] The lower elastic body 38b is made of rubber and has an inner edge portion 38b1 that is joined to the second coupler 39, a semicircular portion 38b2 that has a substantially semicircular cross-sectional shape that is convex downward, and an outer edge portion 38b3.

[0046] The second coupler 39 comprises an inner edge portion 39a joined to the second bobbin 31, an upper joining portion 39c to which the upper elastic body 38a is joined, a lower joining portion 39e to which the lower elastic body 38b is joined, a first connecting portion 39b connecting the inner edge portion 39a and the upper joining portion 39c, and second connecting portions 39d1, 39d2 connecting the upper joining portion 39c and the lower joining portion 39e.

[0047] The inner edge 39a has a shape that slopes downward toward the inside in the radial direction. The inner edge 39a is joined to the second bobbin 31 with an adhesive or the like (not shown). Since the inner edge 39a has a shape that slopes downward toward the inside in the radial direction, adhesive is allowed to accumulate on the upper side of the inner edge 39a.

[0048] The upper joint portion 39c has a cylindrical shape extending parallel to the axial direction. In other words, the thickness direction of the upper joint portion 39c is oriented in the radial direction. The outer peripheral surface of the upper joint portion 39c is joined to the upper elastic body 38a.

[0049] The lower joint portion 39e is located radially outward and below the upper joint portion 39c. The thickness direction of the lower joint portion 39e is oriented in the axial direction. The upper surface of the lower joint portion 39e is joined to the lower elastic body 38b.

[0050] The first connecting portion 39b radially connects the outer edge of the inner edge portion 39a to the upper end of the upper joint portion 39c. The thickness direction of the first connecting portion 39b is oriented in the axial direction.

[0051] The second connecting portions 39d1, 39d2 each have a radially outward extending portion 39d1 and an inclined portion 39d2. The radially outward extending portion 39d1 extends radially outward from the lower end of the upper connecting portion 39c. The inclined portion 39d2 extends diagonally downward and radially outward from the outer edge of the radially outward extending portion 39d1. The inclined portion 39d2 connects to the inner edge of the lower connecting portion 39e.

[0052] Although not shown in the drawings, a through hole is formed in the second coupler 39, penetrating the second coupler 39 in the thickness direction. This through hole is formed, for example, in the first connecting portion 39b or the second connecting portions 39d1 and 39d2 (inclined portion 39d2).

[0053] The outer edge of the second elastic support member 37 is joined to the frame 50. Specifically, an outer edge 38a3 of the upper elastic body 38a is joined to the frame 50, and an outer edge 38b3 of the lower elastic body 38b is joined to the frame 50.

[0054] The second coupler 39 is, for example, a resin molded part, and is a member that is less likely to deform than the upper elastic body 38 a and the lower elastic body 38 b. Even if the second bobbin 31 is displaced in the axial direction, the relative positional relationship between the second bobbin 31, the second coil 32, and the second coupler 39 basically does not change.

[0055] In either the state where the second bobbin 31 is in the initial position (see FIG. 2 ) or the state where the second bobbin 31 is displaced (not shown), the upper joint portion 39c of the second coupler 39 is located above the upper end of the second coil 32. Therefore, in either of the above states, the inner edge portion 38a1 of the upper elastic body 38a is located above the upper end of the second coil 32.

[0056] In either the state where the second bobbin 31 is in the initial position or the state where the second bobbin 31 is displaced, the lower joint portion 39e of the second coupler 39 is located below the upper end of the second coil 32. Therefore, in either of the above states, the inner edge portion 38b1 of the lower elastic body 38b is located below the upper end of the second coil 32.

[0057] 3, the magnetic circuit 40 includes a first magnetic member 41, a first magnet 42, a second magnetic member 43, a second magnet 44, and a third magnetic member 45. These magnetic members 41, 43, and 45 and the magnets 42 and 44 are joined together with an adhesive or the like.

[0058] The magnetic circuit 40 has a first magnetic gap G1 and a second magnetic gap G2. Both the first magnetic gap G1 and the second magnetic gap G2 are open on the upper side. The second magnetic gap G2 is located radially outward of the first magnetic gap G1.

[0059] The magnetic circuit 40 is integrally formed. That is, the magnetic circuit 40 includes the first magnetic gap G1 and the second magnetic gap G2.

[0060] The magnetic circuit 40 forms a first magnetic path 71 and a second magnetic path 72. The first magnetic path 71 is a magnetic path that passes through both the first magnetic gap G1 and the second magnetic gap G2. The second magnetic path 72 is a magnetic path that passes through only the second magnetic gap G2 out of the first magnetic gap G1 and the second magnetic gap G2.

[0061] The portion of the first magnetic path 71 between the outer forming surface G1b of the first magnetic gap G1 and the inner forming surface G2a of the second magnetic gap G2 is formed by the second magnetic member 43. The portion of the first magnetic path 71 between the outer forming surface G2b of the second magnetic gap G2 and the inner forming surface G1a of the first magnetic gap G1 is formed by the third magnetic member 45, the first magnet 42, and the first magnetic member 41. Hereinafter, the third magnetic member 45, the first magnet 42, and the first magnetic member 41 may be collectively referred to as the detour magnetic path forming portions 41, 42, 45. Note that the inner forming surface of the magnetic gap refers to the surface located radially inward of the magnetic gap, and the outer forming surface of the magnetic gap refers to the surface located radially outward of the magnetic gap.

[0062] The portion of the second magnetic path 72 that does not overlap with the first magnetic path 71 is formed by the second magnet 44. The second magnetic member 43 and the detour magnetic path forming portions 41, 42, 45 are connected by the second magnet 44, thereby forming the second magnetic path 72 that passes through the second magnetic gap G2 but does not pass through the first magnetic gap G1. The second magnetic member 43 and the detour magnetic path forming portions 41, 42, 45 are connected only by the second magnet 44.

[0063] The third magnetic member 45 has a bottom wall portion 45a, a cylindrical wall portion 45b standing upward from the outer edge of the bottom wall portion 45a, a protrusion 45c protruding upward from the center of the bottom wall portion 45a, and an attachment portion 45d that is attached to the frame 50. The attachment portion 45d protrudes radially outward from the outer peripheral surface of the cylindrical wall portion 45b. The attachment portion 45d is provided near the lower end of the cylindrical wall portion 45b.

[0064] The first magnet 42 is disposed on the upper surface of the protrusion 45c of the third magnetic member 45. The first magnet 42 has a cylindrical shape. The first magnet 42 mainly applies magnetic flux to the first magnetic path 71.

[0065] The second magnet 44 is disposed on the upper surface of the bottom wall portion 45a of the third magnetic member 45. The second magnet 44 is an annular magnet. The second magnet 44, which is an annular magnet, is disposed so as to surround the protrusion 45c of the third magnetic member 45. In other words, the protrusion 45c of the third magnetic member 45 is disposed radially inward of the second magnet 44. The second magnet 44 mainly applies magnetic flux to the second magnetic path 72.

[0066] The second magnetic member 43 is disposed on the upper surface of the second magnet 44. The second magnetic member 43 has a cylindrical tubular portion 43a and an outer protrusion 43b that protrudes radially outward from the lower end of the tubular portion 43a. The inner circumferential surface of the tubular portion 43a defines an outer defining surface G1b of the first magnetic gap G1. The radially outer surface of the outer protrusion 43b defines an inner defining surface G2a of the second magnetic gap G2. The inner diameter of the tubular portion 43a is smaller than the inner diameter of the second magnet 44. The outer diameter of the tubular portion 43a is smaller than the outer diameter of the second magnet 44.

[0067] The first magnetic member 41 is disposed on the upper surface of the first magnet 42. The first magnetic member 41 has a generally cylindrical shape. The outer peripheral surface of the first magnetic member 41 has an inner forming surface G1a of the first magnetic gap G1.

[0068] Specifically, the first magnetic member 41 has a substantially cylindrical main body 41a and a covering 41b that covers the main body 41a. The covering 41b covers a portion of the upper surface and the outer circumferential surface of the main body 41a. The covering 41b functions as the inner surface G1a of the first magnetic gap G1. The covering 41b is made of a non-magnetic material (copper, for example). The covering 41b suppresses the generation of eddy currents in the first magnetic gap G1.

[0069] (Frame 50 ) As shown in FIG. 1 , the frame 50 has a first bottom wall portion 51 , a second bottom wall portion 52 , a third bottom wall portion 53 , a fourth bottom wall portion 54 , and a magnetic circuit support portion 55 .

[0070] The first bottom wall portion 51 is located higher than the second bottom wall portion 52. The second bottom wall portion 52 is located higher than the third bottom wall portion 53. The third bottom wall portion 53 is located higher than the fourth bottom wall portion 54. The fourth bottom wall portion 54 is located higher than the magnetic circuit support portion 55.

[0071] The first bottom wall portion 51 supports the outer edge portion of the edge 25. The second bottom wall portion 52 supports the outer edge portion of the elastic body 27a of the first elastic support portion 27. The third bottom wall portion 53 supports the outer edge portion of the upper elastic body 38a of the second elastic support portion 37. The fourth bottom wall portion 54 supports the outer edge portion of the lower elastic body 38b of the second elastic support portion 37. The magnetic circuit support portion 55 supports the magnetic circuit 40.

[0072] The first bottom wall portion 51, the second bottom wall portion 52, the third bottom wall portion 53, and the fourth bottom wall portion 54 support respective support objects (such as the edge 25) on their upper surfaces. The magnetic circuit support portion 55 is mechanically fixed to the magnetic circuit 40.

[0073] The outer edge of the edge 25 is located radially outward of the outer edge of the elastic body 27 a of the first elastic support portion 27 .

[0074] The outer edge of the upper elastic body 38a of the second elastic support portion 37 is located radially outward from the outer edge of the lower elastic body 38b of the second elastic support portion 37. The outer edge of the lower elastic body 38b of the second elastic support portion 37 is located radially outward from the attached portion 45d of the magnetic circuit 40.

[0075] The outer edge of the elastic body 27a of the first elastic support portion 27 is located radially inward of the outer edge of the upper elastic body 38a of the second elastic support portion 37, and is located radially inward of the outer edge of the lower elastic body 38b of the second elastic support portion 37. In other words, the outer edge of the first elastic support portion 27 is located radially inward of the outer edge of the second elastic support portion 37.

[0076] The frame 50 has a first connecting portion 56 , a second connecting portion 57 , a third connecting portion 58 , and a fourth connecting portion 59 .

[0077] The first connecting portion 56 connects the first bottom wall portion 51 and the second bottom wall portion 52. The second connecting portion 57 connects the second bottom wall portion 52 and the third bottom wall portion 53. The third connecting portion 58 connects the third bottom wall portion 53 and the fourth bottom wall portion 54. The fourth connecting portion 59 connects the fourth bottom wall portion 54 and the magnetic circuit support portion 55.

[0078] The first connecting portion 56 has a first vertical wall 56a extending parallel to the axial direction and a first inclined wall 56b inclined with respect to the axial direction. The second connecting portion 57 has a second vertical wall 57a extending parallel to the axial direction. The third connecting portion 58 has a third inclined wall 58a inclined with respect to the axial direction. The fourth connecting portion 59 has a fourth inclined wall 59a inclined with respect to the axial direction and a fourth bottom wall 59b perpendicular to the axial direction. The lower surface of the fourth bottom wall 59b and the lower surface of the magnetic circuit support portion 55 are flush with each other.

[0079] The first connecting portion 56 extends from the inner edge of the first bottom wall portion 51. The third connecting portion 58 extends from the inner edge of the third bottom wall portion 53. The fourth connecting portion 59 extends from the inner edge of the fourth bottom wall portion 54. Meanwhile, the second connecting portion 57 extends from the outer edge of the second bottom wall portion 52.

[0080] The lower surface of the magnetic circuit support portion 55 is flush with the lower surface of the third magnetic member 45 of the magnetic circuit 40. As a result, the lower surface of the frame 50 is flush with the lower surface of the magnetic circuit 40.

[0081] The frame 50 includes a first frame 50A and a second frame 50B. The first frame 50A and the second frame 50B are molded (resin molded) as separate bodies.

[0082] The first frame 50A has a first bottom wall portion 51, a first connecting portion 56, a second bottom wall portion 52, and a second connecting portion 57. The second frame 50B has a third bottom wall portion 53, a third connecting portion 58, a fourth bottom wall portion 54, a fourth connecting portion 59, and a magnetic circuit support portion 55.

[0083] The second frame 50B also has an outer vertical wall 51B1 disposed radially outward of the second vertical wall 57a of the second connecting portion 57 of the first frame 50A.

[0084] Next, the relationship between the magnetic circuit 40 and the first and second vibrating parts 20 and 30 will be described.

[0085] As shown in FIG. 1 , the first coil 22 of the first vibrating part 20 is disposed in the first magnetic gap G1. The first coil 22 is connected to a transmission path. The action of an electric signal from the transmission path and the magnetic field of the first magnetic gap G1 causes the first bobbin 21 to vibrate together with the first coil 22, which in turn causes the first vibrating part 20, including the diaphragm 24, to vibrate. This causes sound to be emitted. At this time, a vibration force is generated in the speaker 10 in response to the vibration of the first vibrating part 20. This vibration force is transmitted via the frame 50, causing the entire speaker 10 and the object to which the speaker 10 is attached (for example, the panel of a side door of an automobile) to vibrate.

[0086] The second coil 32 of the second vibrating part 30 is disposed in the second magnetic gap G2. The second coil 32 is connected to a transmission path, and the action of an electric signal from the transmission path and the magnetic field of the second magnetic gap G2 causes the second bobbin 31 to vibrate together with the second coil 32, which in turn causes the second vibrating part 30 to vibrate. The first vibrating part 20 and the second vibrating part 30 are configured to operate in opposite phases to each other. This cancels out the excitation forces generated in response to the vibration of the first vibrating part 20, thereby suppressing vibration of the entire speaker 10.

[0087] <Operation and Effect> Next, the operation and effect of this embodiment will be described.

[0088] In this embodiment, as shown in FIG. 1 , the speaker 10 includes a first vibrating section 20, a second vibrating section 30, a magnetic circuit 40, and a frame 50. The frame 50 supports the first vibrating section 20, the second vibrating section 30, and the magnetic circuit 40. The first vibrating section 20 includes a first coil 22, a first bobbin 21 on which the first coil 22 is provided, and a first elastic support portion 27 that elastically supports the first bobbin 21 so as to allow axial displacement. The second vibrating section 30 includes a second coil 32 having a diameter larger than that of the first coil 22, a second bobbin 31 on which the second coil 32 is provided, and a second elastic support portion 37 that elastically supports the second bobbin 31 so as to allow axial displacement. The magnetic circuit 40 includes a first magnetic gap G1 in which the first coil 22 is disposed, and a second magnetic gap G2 in which the second coil 32 is disposed. The first magnetic gap G1 is open on the upper side, and the second magnetic gap G2 is open on the upper side.

[0089] 1, the second elastic support portion 37 includes an upper elastic body 38a and a lower elastic body 38b, so that the second vibrating portion 30 can vibrate in a stable position.

[0090] Incidentally, when the second elastic support portion 37 includes an upper elastic body 38a and a lower elastic body 38b, and the upper elastic body 38a and the lower elastic body 38b are each joined to the second bobbin 31, it is necessary to elongate the portion of the second bobbin 31 that is located outside the magnetic circuit 40 in the axial direction. This results in an increase in the axial size of the second vibrating portion 30, and therefore an increase in the overall size of the speaker 10. Therefore, in this embodiment, as shown in FIG. 1 , the second vibrating portion 30 further includes a second coupler 39 that connects the second bobbin 31 and the upper elastic body 38a and also connects the second bobbin 31 and the lower elastic body 38b. Therefore, the upper elastic body 38a and the lower elastic body 38b are connected to the second bobbin 31 via the second coupler 39. Therefore, it is not necessary to elongate the portion of the second bobbin 31 that is located outside the magnetic circuit 40 in the axial direction, and this allows the speaker 10 to be made smaller in size in the axial direction.

[0091] 2, in this embodiment, the entire lower elastic body 38b is located below the upper end of the second coil 32. Therefore, the space radially outward from the magnetic circuit 40 and below the upper end of the second magnetic gap G2 can be effectively used as the space in which the lower elastic body 38b is disposed.

[0092] In this embodiment, an air hole may be formed in the second coupler 39 between the connection position (upper joint 39c) of the upper elastic body 38a and the connection position (lower joint 39e) of the lower elastic body 38b. In this case, it is possible to prevent the vibration of the second vibrating part 30 from being hindered by the influence of air resistance.

[0093] 2, the first elastic support portion 27 has a recess 27a22 for avoiding interference with the second bobbin 31. This allows the first vibrating portion 20 and the second vibrating portion 30 to be closer to each other in the axial direction, making it easier to reduce the size of the speaker 10 in the axial direction.

[0094] In this embodiment, as shown in FIG. 3 , the magnetic circuit 40 forms a first magnetic path 71 and a second magnetic path 72. The first magnetic path 71 is a magnetic path that passes through both the first magnetic gap G1 and the second magnetic gap G2. The second magnetic path 72 is a magnetic path that passes only through the second magnetic gap G2. The magnetic circuit 40 includes a second magnetic member 43 that forms a portion of the first magnetic path 71 between the outer surface G1b of the first magnetic gap G1 and the inner surface G2a of the second magnetic gap G2, and detour magnetic path forming portions 41, 42, and 45 that form a portion of the first magnetic path 71 between the outer surface G2b of the second magnetic gap G2 and the inner surface G1a of the first magnetic gap G1. The detour magnetic path forming portions 41, 42, and 45 each include a first magnet 42 that mainly provides magnetic flux to the first magnetic path 71. Therefore, the first magnet 42 can ensure the magnetic flux density of the first magnetic gap G1 and the second magnetic gap G2.

[0095] In this embodiment, the magnetic circuit 40 also includes a second magnet 44. The second magnet 44 mainly applies magnetic flux to the second magnetic path 72. Therefore, the second magnet 44 can ensure the magnetic flux density of the second magnetic gap G2.

[0096] In addition, in this embodiment, the second magnetic member 43 and the detour magnetic path forming portions 41, 42, 45 are connected only by the second magnet 44. Therefore, it is difficult to form a magnetic path (third magnetic path) that passes only through the first magnetic gap G1 of the first magnetic gap G1 and the second magnetic gap G2, and as a result, it is easier to ensure the magnetic flux density of the second magnetic gap G2.

[0097] 1, in this embodiment, the first vibrating section 20 is a driving section for producing sound, and the second vibrating section 30 is a driving section for canceling out vibration of the entire speaker 10 caused by the first vibrating section 20. Therefore, vibration of the entire speaker 10 can be suppressed.

[0098] (Modifications) In the above-described embodiment, the recess 27a22 of the first elastic support portion 27 is provided in the elastic body 27a. However, the recess of the present disclosure is not limited to this. Modifications will be described below.

[0099] 4 shows a speaker 110 according to Modification 1. Components having the same or similar functions as those of the speaker 10 according to the above embodiment are denoted by the same reference numerals.

[0100] In the first modification, the first elastic support portion 27 includes an elastic body 27a and a first coupler 29 that connects the elastic body 27a to the first bobbin 21. The first coupler 29 has a recess 29a for avoiding interference with the second bobbin 31. Therefore, compared to an embodiment in which the elastic body 27a has the recess 27a22, the recess 29a can be formed to be less likely to deform.

[0101] Furthermore, in the first modification, the recess 27a22 is configured to allow at least a portion of the second coupler 39 to enter. This allows the first vibrating part 20 and the second vibrating part 30 to be brought even closer together in the axial direction. This makes it easier to reduce the size of the speaker 10 in the axial direction.

[0102] Moreover, in the first modification, the first vibrating section 20 includes a diaphragm 24. The diaphragm 24 is connected to the first bobbin 21 without the first coupler 29. Therefore, compared to an embodiment in which the diaphragm 24 is connected to the first bobbin 21 via the first coupler 29, the vibration of the first bobbin 21 can be transmitted to the diaphragm 24 more directly. In other words, the audio signal can be transmitted to the diaphragm 24 with less loss.

[0103] 5 shows a speaker 210 according to Modification 2. Note that components having the same or similar functions as those of the speaker 10 according to the above embodiment are given the same reference numerals.

[0104] In the second modification, similar to the speaker 10 according to the above embodiment, the second elastic support portion 37 includes an upper elastic body 38 a and a lower elastic body 38 b, which allows the second vibrating portion 30 to vibrate in a stable position.

[0105] Furthermore, in the second modification, the second vibrating section 30 further includes a second coupler 39 that connects the second bobbin 31 and the upper elastic body 38a and also connects the second bobbin 31 and the lower elastic body 38b. Therefore, the upper elastic body 38a and the lower elastic body 38b are connected to the second bobbin 31 via the second coupler 39. Therefore, it is not necessary to form the portion of the second bobbin 31 that is disposed outside the magnetic circuit 40 long in the axial direction, and therefore the speaker 210 can be made smaller in size in the axial direction.

[0106] In addition, in the second modification, an air hole 39H is formed in the second coupler 39 between the connection position (upper joint 39c) of the upper elastic body 38a and the connection position (lower joint 39e) of the lower elastic body 38b. This makes it possible to prevent the vibration of the second vibrating part 30 from being hindered by the influence of air resistance.

[0107] In the second modification, the magnetic circuit 40 includes a first magnetic circuit 40A having a first magnetic gap G1 in which the first coil 22 is disposed, and a second magnetic circuit 40B having a second magnetic gap G2 in which the second coil 32 is disposed. The frame 50 includes a first frame 50A to which the first vibrating part 20 and the first magnetic circuit 40A are attached, and a second frame 50B to which the second vibrating part 30 and the second magnetic circuit 40B are attached. Therefore, the speaker 210 can be manufactured by separately assembling a component including the first vibrating part 20, the first magnetic circuit 40A, and the first frame 50A and a component including the second vibrating part 30, the second magnetic circuit 40B, and the second frame 50B, and then combining the two components. In other words, the speaker 210 is manufactured with consideration given to the manufacturing process.

[0108] [Supplementary Explanation] Although the preferred embodiments of the present disclosure have been described above, the present disclosure is not limited to the above-described embodiments.

[0109] In the above embodiment, the magnetic circuit 40 has the structure shown in Fig. 3. However, the magnetic circuit of the present disclosure is not limited to this.

[0110] In the above embodiment, the upper elastic body 38a is made of cloth and the lower elastic body 38b is made of rubber. However, the present disclosure is not limited to this. The upper elastic body 38a may be made of rubber and the lower elastic body 38b may be made of cloth. In the second elastic support portion 37, by making one of the upper elastic body 38a and the lower elastic body 38b out of rubber, the sagging of the second elastic support portion as a whole can be suppressed compared to, for example, an embodiment in which both the upper elastic body and the lower elastic body are made of cloth. Furthermore, in the second elastic support portion 37, by making one of the upper elastic body 38a and the lower elastic body 38b out of cloth, the center holding force of the second elastic support portion relative to the second bobbin 31 can be improved compared to, for example, an embodiment in which both the upper elastic body and the lower elastic body are made of rubber.

[0111] Furthermore, the first bobbin 21 is elastically supported not only by the first elastic support portion 27 including the elastic body 27a made of cloth, but also by the edge 25 made of rubber. In this configuration, by making one of the upper elastic body 38a and the lower elastic body 38b of the second elastic support portion 37 out of rubber, it is possible to match the characteristic changes over time between the member that elastically supports the first bobbin 21 and the member that elastically supports the second bobbin 31. This makes it possible to suppress deterioration in the performance of the second vibrating portion 30 (i.e., the function of canceling out the vibration of the entire speaker 210 caused by the first vibrating portion 20).

[0112] Furthermore, the present disclosure is not limited to the above, and the upper elastic body 38a and the lower elastic body 38b may both be made of cloth, or may both be made of rubber.

[0113] REFERENCE SIGNS LIST 10 Speaker 20 First vibrating part 21 First bobbin 22 First coil 24 Diaphragm 27 First elastic support part 27a Elastic body 27a22 Recess 29 First coupler 30 Second vibrating part 31 Second bobbin 32 Second coil 37 Second elastic support part 38a Upper elastic body 38b Lower elastic body 39 Second coupler 40 Magnetic circuit 41 First magnetic member 42 First magnet 43 Second magnetic member 44 Second magnet 45 Third magnetic member 50 Frame 110 Speaker 29a Recess G1 First magnetic gap G1a Inner forming surface G1b Outer forming surface G2 Second magnetic gap G2a Inner forming surface G2b Outer forming surface

Claims

1. A speaker comprising: a first vibration section; a second vibration section; a magnetic circuit; and a frame supporting the first vibration section, the second vibration section, and the magnetic circuit, wherein the first vibration section comprises: a first coil; a first bobbin on which the first coil is provided; and a first elastic support section that elastically supports the first bobbin so as to be displaceable in the axial direction; the second vibration section comprises: a second coil having a diameter larger than that of the first coil; a second bobbin on which the second coil is provided; and a second elastic support section that elastically supports the second bobbin so as to be displaceable in the axial direction; the magnetic circuit comprises: a first magnetic gap in which the first coil is disposed; and a second magnetic gap in which the second coil is disposed; the first magnetic gap is open upward; and the second magnetic gap is open upward; the second elastic support section comprises: an upper elastic body; a lower elastic body provided below the upper elastic body; and a second coupler that connects the second bobbin to the upper elastic body and also connects the second bobbin to the lower elastic body; A speaker.

2. The speaker according to claim 1, wherein at least a portion of the lower elastic body is located below an upper end of the second coil.

3. The speaker according to claim 1, wherein the second coupler has an air hole formed between the connection position of the upper elastic body and the connection position of the lower elastic body.

4. The speaker according to claim 1, wherein the first elastic support portion has a recess for avoiding interference with the second bobbin.

5. A speaker as described in claim 1, wherein the first elastic support portion comprises: an elastic body; and a first coupler that connects the elastic body and the first bobbin, and the first coupler has a recess for avoiding interference with the second bobbin.

6. The speaker according to claim 5, wherein the first vibrating portion comprises a diaphragm, and the diaphragm is connected to the first bobbin without the first coupler.

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