Loudspeaker

Abstract

The invention provides a loudspeaker having a structure suitable for thinning. A speaker (10) is provided with a magnetic circuit (40), a first vibration unit (20), and a second vibration unit (30). The magnetic circuit (40) has a first magnet (42), a first magnetic member (41) attached to the first magnet (42), a first yoke (43) attached to the first magnet (42), and a second yoke (45). The first yoke (43) forms a first magnetic gap (G1) between the first yoke (43) and the first magnetic member (41), and forms a second magnetic gap (G2) between the first yoke (43) and the second yoke (45). In addition, the second vibrating part (30) is provided with a weight (39).

Description

Technical Field

[0001] The present invention relates to loudspeakers. Background Art Patent Document 1 discloses a speaker device for achieving high-quality sound reproduction.

[0002] This speaker device includes a first magnetic circuit, a main body that emits sound waves, a second magnetic circuit integrally formed with the first magnetic circuit, and a vibration suppression unit. The main body includes a first vibrating unit driven by the first magnetic circuit, while the vibration suppression unit includes a second vibrating unit driven in a direction opposite to the first vibrating unit by the second magnetic circuit. The second vibrating unit applies vibrations to the second magnetic circuit that cancel out the vibrations applied to the first magnetic circuit by the first vibrating unit. [Prior art literature] [Patent Document]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2006-13587 Summary of the Invention [Problems to be Solved by the Invention]

[0004] In the above-mentioned technologies, there is room for improvement in reducing the thickness of the speaker. An object of the present disclosure is to provide a loudspeaker having a structure suitable for thinning. [Means for solving the problem]

[0005] The speaker of the first scheme comprises: a magnetic circuit; a first vibrating part, which vibrates in order to produce sound, and has a first voice coil frame, a first coil, a first damper and a vibration plate; and a second vibrating part, which vibrates in order to offset the vibration of the entire speaker caused by the first vibrating part, and has a second voice coil frame, a second coil, a second damper and a counterweight, the magnetic circuit comprises: a first magnet; a first magnetic component, which is mounted on the first magnet; a first yoke, which is mounted on the first magnet and forms a first magnetic gap between it and the first magnetic component; and a second yoke, which forms a second magnetic gap between it and the first yoke, the counterweight is composed of a conductor as a non-magnetic component, and the shape of the counterweight is roughly annular with a cutout on a part of its circumference.

[0006] In this aspect, the speaker includes: a magnetic circuit; a first vibrating portion that vibrates to generate sound; and a second vibrating portion that vibrates to cancel vibration of the entire speaker caused by the first vibrating portion. The first vibrating portion includes a first voice coil bobbin, a first coil, and a first damper, and the second vibrating portion includes a second voice coil bobbin, a second coil, and a second damper.

[0007] In this embodiment, the magnetic circuit includes a first magnet, a first magnetic member, a first yoke, and a second yoke. The first yoke forms a first magnetic gap with the first magnetic member and a second magnetic gap with the second yoke. Therefore, the first yoke can be used as a path for both the magnetic flux passing through the first magnetic gap and the magnetic flux passing through the second magnetic gap, and the thickness of the magnetic circuit can be reduced.

[0008] Here, the second vibrating part has a weight. Therefore, compared to a configuration where the second vibrating portion does not have a counterweight, the amplitude of the second vibrating portion can be reduced while maintaining the force generated by the second vibrating portion. As a result, the speaker can be made thinner. Furthermore, thinning a speaker means miniaturizing the speaker in the vibration direction of the first vibrating portion, i.e., reducing the overall height of the speaker. In addition, the weight is made of a conductive material such as metal. Therefore, it is easy to ensure the mass of the weight and the force generated by the second vibrating part. Furthermore, the counterweight is made of a non-magnetic member such as aluminum. This prevents the counterweight from receiving an unnecessary force from the magnetic field generated by the magnetic circuit. Furthermore, the weight is in a substantially annular shape with a notch partially formed on its circumference. Therefore, when the second magnet is magnetized, current can be prevented from flowing in a circular shape through the weight, thereby preventing a strong force from acting on the weight.

[0009] A second aspect of the speaker is characterized in that, in the first aspect, the second voice coil bobbin protrudes upward relative to the weight.

[0010] In this embodiment, the second voice coil bobbin protrudes upward relative to the weight. In other words, the weight does not protrude upward relative to the second voice coil bobbin, that is, toward the first vibrating part. Therefore, compared with a configuration in which a weight is arranged so as to be hooked on the upper end of the second voice coil bobbin, for example, it is easier to reduce the thickness of the speaker.

[0011] According to a third aspect of the speaker, in the first or second aspect, the second damper includes two elastic bodies, and the weight is disposed between the two elastic bodies.

[0012] In this embodiment, the second damper includes two elastic bodies, so that the second vibrating portion has improved movement symmetry and straightness during vibration. Furthermore, the weight is placed between the two elastic bodies, so it does not adversely affect the thinness of the speaker.

[0013] The speaker involved in the fourth embodiment is any one of the first to third embodiments, wherein the second damper has a first elastomer and a second elastomer arranged in an overlapping manner in the vibration direction, the first elastomer has a recessed portion recessed in a direction close to the second elastomer in the vibration direction, and the counterweight is arranged on a surface on the side opposite to the second elastomer in the recessed portion.

[0014] In this embodiment, the second damper includes a first elastic body and a second elastic body arranged to overlap in the vibration direction. Furthermore, the first elastic body includes a recessed portion that is recessed in the direction toward the second elastic body in the vibration direction, and the counterweight is disposed on a surface of the recessed portion opposite to the second elastic body. Therefore, it is unnecessary to arrange a weight between the first elastic body and the second elastic body, and it is possible to suppress an increase in the size of the second vibrating portion in the amplitude direction.

[0015] A fifth aspect of the loudspeaker is characterized in that, in any one of the first to fourth aspects, the weight is arranged to surround the second voice coil bobbin. The weight is radially spaced apart from the second voice coil bobbin. The weight has a recessed portion in a portion of the circumference thereof that increases the distance from the second voice coil bobbin.

[0016] In this aspect, the weight has a recessed portion in a portion in the circumferential direction thereof for increasing the distance between the weight and the second voice coil bobbin. Therefore, when welding the outer peripheral surface of the second voice coil bobbin, providing the recessed portion corresponding to the welding location can suppress short circuits between the second voice coil bobbin and the weight caused by solder slag or other metal members.

[0017] A speaker according to a sixth aspect is the speaker according to any one of the first to fifth aspects, wherein the center of gravity of the weight is substantially the same as the central axis of the second vibrating part.

[0018] In this embodiment, the center of gravity of the weight is substantially the same as the central axis of the second vibrating part. Therefore, the straightness of the vibration of the second vibrating portion can be satisfied.

[0019] A speaker according to a seventh aspect is any one of the first to sixth aspects, wherein the second damper includes an elastic body integrated with a wiring.

[0020] In this aspect, the second damper includes an elastic body integrated with the wiring. Therefore, there is no need to provide a space for wiring, which contributes to the reduction in thickness of the speaker. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a cross-sectional view of the speaker according to the first embodiment. Figure 2 This is an exploded perspective view of the first vibrating part. Figure 3 This is an exploded perspective view of the second vibrating part. Figure 4 is a perspective view of the coupler. Figure 5 This is a cut-off end view of the coupler. Figure 6 It is a three-dimensional diagram of the counterweight. Figure 7 This is a partial enlarged view of the frame. Figure 8 It is a cross-sectional view of a speaker according to a second embodiment. Figure 9 It is a perspective view showing a counterweight according to a modified example. DETAILED DESCRIPTION

[0022] (First embodiment) Will refer to Figures 1 to 7 A speaker 10 according to a first embodiment of the present disclosure will be described. Figure 1 It is a cross-sectional view taken along the XZ plane passing through the central axis O1 of the speaker 10 .

[0023] The speaker 10 is mounted on a vehicle door, for example. The speaker 10 is, for example, a woofer or a subwoofer, capable of reproducing bass sounds even with a large input. The main portion of the speaker 10 is axially symmetrical about a central axis O1.

[0024] The speaker 10 includes a first vibrating part 20 that vibrates to generate sound, a second vibrating part 30 that vibrates to cancel 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 parts.

[0025] In the following description, the direction parallel to the central axis O1 is referred to as the axial direction. The direction from the second vibrating portion 30 toward the first vibrating portion 20 within the axial direction is referred to as the front direction or the upper direction. The direction from the first vibrating portion 20 toward the second vibrating portion 30 is referred to as the rear direction or the lower direction. Furthermore, the direction perpendicular to the central axis O1 is referred to as the radial direction.

[0026] (First Vibrating Part 20) The first vibrating part 20 includes a first voice coil bobbin 21 , a first coil 22 , a first damper 27 , a diaphragm 24 , an edge 25 , a cover 26 , and a coupler 23 .

[0027] The first voice coil bobbin 21 has a cylindrical shape coaxial with the central axis O1 . The first coil 22 is formed by being wound around the outer peripheral surface of the rear end portion of the first voice coil bobbin 21 .

[0028] The diaphragm 24 is a member that radiates sound by vibrating. The diaphragm 24 has a circular hole in the center that is coaxial with the central axis O1 and has a shape that extends radially outward and forward from an inner edge portion 24a forming the circular hole. The inner edge portion 24 a of the vibration plate 24 is joined to the coupler 23 . Outer edge 24b of diaphragm 24 is connected to frame 50 via edge 25. Inner edge 25a of edge 25 is bonded to the front surface of outer edge 24b of diaphragm 24. Edge 25 is annular, with a forward-convex U-shaped cross-section. Outer edge 27b of edge 25 is bonded to frame 50.

[0029] The first damper 27 supports the first voice coil bobbin 21 so as to be vibrable in the direction of the central axis O1 . The first damper 27 is arranged radially outward of the first voice coil bobbin 21 and behind the diaphragm 24 . The first damper 27 is composed of an elastic body 27A. The elastic body 27A is an annular disk-shaped elastic body having a circular hole coaxial with the central axis O1 at the center and extending radially outward from the inner edge 27a forming the circular hole. The elastic body 27A has a corrugated shape (specifically, a shape that undulates back and forth depending on the radial position). The inner edge 27a of the elastic body 27A and the outer edge of the coupler 23 (the fourth horizontal portion 69, see Figure 5 ) is joined to the front surface, and the outer edge portion 27b of the elastic body 27A is joined to the frame 50.

[0030] like Figure 2 As shown, two strip-shaped wirings 81 (wiring, transmission path) are integrated with the elastic body 27A. Each strip-shaped wiring 81 is provided on the front surface side of the elastic body 27A in a manner along the shape of the elastic body 27A. That is, each strip-shaped wiring 81 has a wavy shape. The two strip-shaped wirings 81 are arranged at positions symmetrical in the Y direction and extend parallel to the X direction. The inner connecting portion 82a of the strip-shaped wiring 82 is connected to the second extending portion 23c of the relay member 23c described later (see FIG. Figure 4 )connect.

[0031] The cover 26 is a member that radiates sound by vibrating. The cover 26 covers the first bobbin 21 and the coupler 23 from the front. The outer edge of the cover 26 is bonded to the front surface of the vibration plate 24.

[0032] The coupler 23 is a member that radiates sound by vibrating. The coupler 23 is disposed on the outer periphery of the first voice coil bobbin 21 and connects the first voice coil bobbin 21 to the diaphragm 24 and to the first damper 27 .

[0033] like Figure 4 As shown, the coupler 23 basically has an axisymmetrical structure with respect to the central axis O1. like Figure 5 As shown, the coupler 23 has, from the inner edge toward the outer edge, a first horizontal portion 61, a first vertical wall portion 62, a first inclined portion 63, a second horizontal portion 64, a second vertical wall portion 65, a third horizontal portion 66, a second inclined portion 67, a third vertical wall portion 68, and a fourth horizontal portion 69. These components have an axisymmetrical shape with respect to the central axis O1, except for the portion where the recessed portion 23b described later is formed.

[0034] The first horizontal portion 61 extends slightly radially inward from the rear end of the first vertical wall portion 62. The first horizontal portion 61 forms a circular hole coaxial with the central axis O1. When the first voice coil bobbin 21 is inserted into the circular hole, the outer circumference of the first voice coil bobbin 21 is bonded to the first horizontal portion 61 and the first vertical wall portion 62.

[0035] The first vertical wall portion 62 has a cylindrical shape. A small radial gap is formed between the inner peripheral surface of the first vertical wall portion 62 and the outer peripheral surface of the first voice coil bobbin 21. The adhesive flows into this gap.

[0036] The first inclined portion 63 has a shape that is inclined forward toward the radially outer side. The first inclined portion 63 facilitates the introduction of an adhesive for bonding the first voice coil bobbin 21 and the coupler 23 .

[0037] The second horizontal portion 64 is a portion extending radially outward from the front end of the first inclined portion 63 .

[0038] The second vertical wall portion 65 has a cylindrical shape. The inner edge portion 24 a of the vibration plate 24 is joined to the outer peripheral surface of the second vertical wall portion 65 . The first inclined portion 63, the second horizontal portion 64, and the second vertical wall portion 65 form a relief portion 23a. The relief portion 23a is provided to prevent interference between the coupler 23 and the second bobbin 31 during operation of the loudspeaker 10. Specifically, the relief portion 23a is a portion of the first vibrating portion 20 that is shaped to avoid interference with the second voice coil bobbin 31.

[0039] The third horizontal portion 66 slightly extends radially outward from the rear end of the second vertical wall portion 65. The second inclined portion 67 is shaped to be inclined radially outward and rearward. The third vertical wall portion 68 slightly extends rearward from the rear end of the second inclined portion 67.

[0040] The fourth horizontal portion 69 extends radially outward from the rear end of the third vertical wall portion 68. The fourth horizontal portion 69 constitutes the outer edge of the coupler 23. The elastic body 27A of the first damper 27 is bonded to the front surface of the fourth horizontal portion 69 by adhesive or the like.

[0041] like Figure 4As shown, coupler 23 has two recesses 23b. These two recesses 23b are formed symmetrically in the Y direction. The front surface of coupler 23 is recessed rearward or radially inward in the portion where recesses 23b are formed. When viewed from the front, i.e., in the +Z direction, each recess 23b is formed in a region extending in the X direction.

[0042] Specifically, the recessed portion 23b has a first horizontal surface 23b1, a longitudinal surface 23b2, and a second horizontal surface 23b3. The first horizontal surface 23b1 is formed by the front surface of the second horizontal portion 64 being recessed rearward, with its normal facing forward. The longitudinal surface 23b2 is formed by the second longitudinal wall portion 65, the third horizontal portion 66, the second inclined portion 67, and the third longitudinal wall portion 68 being recessed radially inward, with its normal facing radially outward. The second horizontal surface 23b3 is formed by the third horizontal portion 66, the second inclined portion 67, and the third longitudinal wall portion 68 being recessed rearward, with its normal facing forward. The second horizontal surface 23b3 is flush with the front surface of the fourth horizontal portion 69.

[0043] The coupler 23 is formed by insert molding with two relay members 23c as inserts. The two relay members 23c are conductive members and are arranged at positions corresponding to the two recessed portions 23b. The two relay members 23c have the same structure. The relay member 23c is formed by bending a long, strip-shaped plate. It has a first extension 23c1 extending in the axial direction and a second extension 23c2 extending perpendicular to the axial direction (the X direction). The plate forming the relay member 23c is bent at a right angle at the rear end of the first extension 23c1, and the second extension 23c2 extends from this portion in the +X direction.

[0044] A portion of the front end of the first extension portion 23c1 protrudes forward from the first horizontal surface 23b1 of the recessed portion 23b of the coupler 23. A wiring (not shown) connected to the first coil 22 is connected to this portion by welding. Thus, since a portion of the front end of the first extension portion 23c1 protrudes forward from the first horizontal surface 23b1 of the recessed portion 23b, the front-to-back dimension of the first extension portion 23c1 can be reduced while maintaining the front-to-back dimension of the protruding portion.

[0045] The front surface of a portion of the second extension portion 23c on the +X direction side is exposed at the second horizontal surface 23b3 of the recess 23b of the coupler 23 and the front surface of the fourth horizontal portion 69, and the inner connecting portion 81a of the strip wiring 81 integrated with the elastic body 27A of the first damper 27 is joined to this portion by welding.

[0046] (Second Vibrating Part 30) like Figure 1 、 Figure 3As shown, the second vibration part 30 includes a second voice coil bobbin 31 , a second coil 32 , a second damper 37 , a spacer 38 , and a weight 39 .

[0047] The second voice coil bobbin 31 has a cylindrical shape coaxial with the central axis O1 and has a diameter greater than that of the first voice coil bobbin 21 . The second coil 32 is formed by being wound around the outer peripheral surface of the rear end portion of the second voice coil bobbin 31 . exist Figure 1 In the non-operating state shown (a state in which the loudspeaker 10 is not operating), the front end of the second voice coil bobbin 31 is located forward of the rear end of the first voice coil bobbin 21 .

[0048] The second damper 37 supports the second voice coil bobbin 31 so as to be vibrable in the axial direction relative to the frame 50 . The second damper 37 includes a first elastic body 37A and a second elastic body 37B, spaced apart from each other in the axial direction. Both the first elastic body 37A and the second elastic body 37B are circular plates with a central hole coaxial with the central axis O1, extending radially outward from the inner edge of the hole. These elastic bodies have a corrugated shape. The first elastic body 37A and the second elastic body 37B have substantially the same structure. Therefore, when the first elastic body 37A and the second elastic body 37B are moved parallel to each other in the axial direction, their cross-sectional shapes overlap. A spacer 38 is provided on the outer edge of the second damper 37 to maintain the axial distance between the first elastic body 37A and the second elastic body 37B. The rear surface of the outer edge of the second elastic body 37B is bonded to the frame 50. The inner edges of the first elastic body 37A and the second elastic body 37B are bonded to the outer circumferential surface of the second voice coil bobbin 31.

[0049] Two strap wirings 82 (wiring, transmission path) are integrated with the first elastic body 37A. Each strap wiring 82 is provided on the front surface side of the first elastic body 37A so as to follow the shape of the first elastic body 37A. In other words, each strap wiring 82 has a corrugated shape. The two strip wirings 82 are arranged at positions symmetrical to each other in the Y direction and extend parallel to each other in the X direction. The inner connecting portion 82 a of the strip wiring 82 is connected to a transmission path formed on the outer peripheral surface of the second voice coil bobbin 31 .

[0050] The counterweight 39 is provided to increase the mass of the portion that is supported and vibrates by the second damper 37. By increasing the mass of the portion that is supported and vibrates by the second damper 37, the amplitude of the second vibrating portion 30 can be reduced while maintaining the effect of the second vibrating portion 30 canceling out the vibration of the entire speaker 10. The counterweight 39 is annular, extending along the cylindrical shape of the second voice coil bobbin 31. It is positioned near the inner edge of the second damper 37. Specifically, it is positioned between the first elastic body 37A and the second elastic body 37B near the inner edge of the second damper 37. Thus, the counterweight 39 is positioned to surround the second voice coil bobbin 31.

[0051] Figure 6 This is an enlarged perspective view of the counterweight 39. The counterweight 39 has two recesses 39a. The recesses 39a increase the distance between the inner circumference of the counterweight 39 and the outer circumference of the second voice coil bobbin 31 in the portion of the circumference where the recesses 39a are formed. The two recesses 39a are formed at positions opposing each other across the center axis O1. One of the two recesses 39a is formed in a region encompassing the location where the inner connecting portion 82a of the two aforementioned ribbon wirings 82 connects to the transmission path formed on the outer circumference of the second voice coil bobbin 31.

[0052] Specifically, the counterweight 39 has a front surface 71, a rear surface 72, an outer circumferential surface 73, and an inner circumferential surface 74. The front surface 71 is a flat surface with its normal facing forward, and the rear surface 72 is a flat surface with its normal facing rearward. The outer circumferential surface 73 is a curved surface with its normal facing radially outward, formed on a circle centered on the central axis O1 when viewed from the axial direction. The inner circumferential surface 74 includes a first inner circumferential surface 74a corresponding to a circumferential position where the recess 39a is not formed, and a second inner circumferential surface 74b corresponding to a circumferential position where the recess 39a is formed. Two first inner circumferential surfaces 74a are formed, and two second inner circumferential surfaces 74b are formed. Both the first inner circumferential surface 74a and the second inner circumferential surface 74b are curved surfaces with their normal facing radially inward, formed on an arc centered on the central axis O1 when viewed from the axial direction. The counterweight 39 also includes a connecting surface 74c that connects the first inner circumferential surface 74a and the second inner circumferential surface 74b. Two connecting surfaces 74c are formed relative to one second inner circumferential surface 74b. The two connecting surfaces 74c face in opposing directions (the Y direction). In other words, the two connecting surfaces 74c are parallel to each other.

[0053] (Magnetic Circuit 40) like Figure 1 As shown, the magnetic circuit 40 includes a first magnetic member 41 (top plate), a first magnet 42, an intermediate magnetic member 43 (first yoke), a second magnet 44, and a second magnetic member 45 (second yoke). The magnetic circuit 40 is formed by stacking the second magnet 44, the intermediate magnetic member 43, the first magnet 42, and the first magnetic member 41 coaxially in this order, starting from the second magnetic member 45 positioned at the rear. By configuring the magnetic circuits corresponding to the first vibrating portion 20 and the second vibrating portion 30 with one magnetic circuit 40 and adopting a structure in which the magnetic circuits 40 are stacked from the rear, assemblability in the manufacturing process is improved.

[0054] The second magnetic member 45 includes a disc-shaped bottom 45a, a cylindrical portion 45b extending forward from the outer edge of the bottom 45a, a cylindrical protrusion 45c protruding forward from the center of the bottom 45a, and a mounting flange 45d extending radially outward from the front end of the cylindrical portion 45b. The mounting flange 45d is mounted on the frame 50. A recess 45a1 is provided on the rear surface of the bottom 45a.

[0055] The second magnet 44 is joined to the front surface of the protrusion 45 c. The second magnet 44 is cylindrical in shape. The diameter of the second magnet 44 is larger than that of the first magnet 42 .

[0056] The intermediate magnetic member 43 is joined to the front surface of the second magnet 44. The intermediate magnetic member 43 has a disc-shaped bottom 43a, a cylindrical portion 43b standing forward from the periphery of the bottom 43a, and a cylindrical protrusion 43c protruding forward from the center of the bottom 43a.

[0057] The first magnet 42 is bonded to the front surface of the protrusion 43c. The first magnet 42 has a cylindrical shape. The diameter of the first magnet 42 is substantially the same as the diameter of the protrusion 43c.

[0058] The first magnetic member 41 is joined to the front surface of the first magnet 42. The first magnetic member 41 is cylindrical in shape. The diameter of the first magnetic member 41 is slightly larger than that of the first magnet 42.

[0059] The diameter of the bottom portion 43a of the intermediate magnetic member 43 is larger than that of the cylindrical portion 43b. Therefore, the outer peripheral portion 43a1 of the bottom portion 43a protrudes radially outward from the outer peripheral surface of the cylindrical portion 43b. The outer peripheral portion 43a1 of the bottom portion 43a is referred to as the outer protruding portion 43a1. On the other hand, the front end of the cylindrical portion 45 b of the second magnetic member 45 and the front surface of the bottom portion 43 a of the intermediate magnetic member 43 are positioned approximately in the front-rear direction. Therefore, the outer protrusion 43 a 1 and the front end portion of the cylindrical portion 43 b of the second magnetic member 45 are opposed to each other in the radial direction.

[0060] The front end of the cylindrical portion 43 b of the intermediate magnetic member 43 is located forward of the front surface of the first magnetic member 41 . An annular gap is formed between the inner circumference of the cylindrical portion 43b of the intermediate magnetic member 43 and the outer circumference of the first magnetic member 41, the first magnet 42, and the protrusion 43c. Within this gap, a substantially uniform magnetic field is generated in the circumferential direction in a first magnetic gap G1 formed between the outer circumference of the first magnetic member 41 and the inner circumference of the cylindrical portion 43b.

[0061] The bottom 43a of the intermediate magnetic member 43, the second magnet 44, and the protrusion 45c of the intermediate magnetic member 43 are located inside the cylindrical portion 45b of the intermediate magnetic member 43. An annular gap is formed between the inner circumference of the cylindrical portion 45b and the outer circumference of the bottom 43a, the second magnet 44, and the protrusion 45c. Within this gap, a substantially uniform magnetic field is generated in the circumferential direction in a second magnetic gap G2 formed by the outer circumference of the bottom 43a (the outer circumference of the outer protrusion 43a1) and the inner circumference of the cylindrical portion 45b. By adjusting the protrusion amount of the outer protrusion 43a1, the interval of the second magnetic gap G2 can be narrowed, the magnetic flux passing through the second magnetic gap G2 can be increased, and the leakage magnetic flux can be reduced.

[0062] (Frame 50) The frame 50 includes a first support portion 51 that supports the outer edge portion 25 b of the rim 25 , a second support portion 52 that supports the outer edge portion 27 b of the first damper 27 , and a third support portion 53 that supports the outer edge portion of the second damper 37 . like Figure 7 As shown, the first support portion 51, the second support portion 52, and the third support portion 53 are all formed continuously on a circumference centered on the central axis O1. The first support portion 51, the second support portion 52, and the third support portion 53 engage with the edge 25, the first damper 27, and the second damper 37 on their respective forward-facing surfaces. The first support portion 51 is located at the front, and the third support portion 53 is located at the rear. The first support portion 51 has the largest diameter, and the third support portion 53 has the smallest diameter.

[0063] The frame 50 has a first connecting portion 55 that connects the first supporting portion 51 and the second supporting portion 52. Figure 7 As shown in FIG. 5 , a plurality of first connection portions 55 are provided in a circumferentially spaced relationship. Therefore, a plurality of first openings 59A are formed between the first support portion 51 and the second support portion 52 .

[0064] The frame 50 has a second connecting portion 56 that connects the second supporting portion 52 and the third supporting portion 53. Figure 7 As shown, a plurality of second connecting portions 56 are provided in the circumferential direction. Therefore, a plurality of second openings 59B are formed between the second support portion 52 and the third support portion 53. The circumferential positions of the second connecting portions 56 coincide with those of the first connecting portions 55.

[0065] The frame 50 includes a fourth support portion 54 that supports the magnetic circuit 40. The fourth support portion 54 is oriented with its thickness oriented in the axial direction. Furthermore, the frame 50 includes a third connecting portion 57 that connects the third support portion 53 and the fourth support portion 54. The third connecting portion 57 is formed continuously in the circumferential direction. Therefore, there is no opening between the third support portion 53 and the fourth support portion 54.

[0066] Next, the relationship between the magnetic circuit 40 , the first vibrating portion 20 , and the second vibrating portion 30 will be described.

[0067] A first coil 22 is disposed in the first magnetic gap G1. The first coil 22 is connected to a transmission path. The electrical signal from the transmission path and the magnetic field of the first magnetic gap G1 cause the first voice coil bobbin 21 to vibrate together with the first coil 22, which in turn causes the first vibrating part 20 to vibrate, producing sound. At this time, the first excitation force is generated in the speaker 10 by the vibration of the first vibrating part 20. This first excitation force causes the housing fixed to the speaker 10 to vibrate.

[0068] A second coil 32 is disposed in the second magnetic gap G2. The second coil 32 is connected to the same transmission path as the first coil 22. The second voice coil bobbin 31 vibrates together with the second coil 32 due to the action of the electrical signal from the transmission path and the magnetic field of the second magnetic gap, thereby vibrating the second vibrating unit 30. The first vibrating portion 20 and the second vibrating portion 30 are configured to operate in opposite phases. Specifically, when the first vibrating portion 20 moves forward, the second vibrating portion 30 moves backward, and when the first vibrating portion 20 moves backward, the second vibrating portion 30 moves forward. This anti-phase operation of the first vibrating portion 20 and the second vibrating portion 30 can be achieved by adjusting the magnetization direction of each magnet, the flow direction of the current, and the winding direction of the coil.

[0069] <Effects> Next, the effects of this embodiment will be described.

[0070] In this embodiment, if Figure 1 As shown, the speaker 10 includes a frame 50, a magnetic circuit 40, and a first vibrating portion 20 that vibrates to produce sound. The first vibrating portion 20 includes a first voice coil bobbin 21, a first coil 22, a first damper 27, and a diaphragm 24. The first coil 22 and the first voice coil bobbin 21 are elastically supported on the frame 50 by the first damper 27. The first coil 22 is driven in conjunction with the magnetic circuit 40, causing the diaphragm 24 to vibrate and produce sound.

[0071] In this embodiment, speaker 10 further includes a second vibrating portion 30 that vibrates to offset the vibration of speaker 10 as a whole caused by first vibrating portion 20. Second vibrating portion 30 includes a second voice coil bobbin 31, a second coil 32, and a second damper 37. Consequently, the vibration of first vibrating portion 20 transmitted to frame 50 is offset. Furthermore, the generation of unnecessary vibration transmitted to frame 50 can be suppressed, thereby suppressing the vibration of speaker 10. As a result, degradation of sound quality caused by the vibration of speaker 10 can be suppressed.

[0072] However, in conventional techniques in which the inner edge 24a of the diaphragm 24 is directly bonded to the first voice coil bobbin 21, a significant inclination is sometimes provided near the inner edge of the diaphragm 24 to ensure adequate rigidity of the diaphragm 24 and suppress reverse vibration. However, providing a significant inclination near the inner edge of the diaphragm 24 increases the height (overall height and front-to-back dimension) of the diaphragm 24, which, in turn, hinders the reduction in thickness of the loudspeaker 10. Therefore, in this embodiment, the first vibrating part 20 includes the coupler 23 . The inner edge 24 a of the diaphragm 24 is radially spaced outward from the outer circumference of the first voice coil bobbin 21 , and the inner edge 24 a of the diaphragm 24 and the first voice coil bobbin 21 are connected via the coupler 23 . Specifically, the vicinity of the inner edge of the diaphragm in the conventional art is replaced with coupler 23. This eliminates the need to increase the height of diaphragm 24, making it easier to maintain the rigidity of the structure consisting of coupler 23 and diaphragm 24. As a result, reverse vibration of diaphragm 24 can be suppressed, allowing for a thinner speaker 10.

[0073] Furthermore, in this embodiment, the coupler 23 includes a relief portion 23a to avoid interference with the second bobbin 31. Therefore, compared to a configuration in which the coupler 23 does not include the relief portion 23a, the first vibrating portion 20 and the second vibrating portion 30 can be positioned closer together. Consequently, the speaker 10 can be made thinner. In particular, although not shown in the figure, in this embodiment, when the first voice coil bobbin 21 and the second voice coil bobbin 31 are closest to each other in the front-rear direction, the front end of the second voice coil bobbin 31 is located in the avoidance portion 23 a.

[0074] In this embodiment, the inner edge 27 a of the first damper 27 is spaced radially outward from the outer peripheral surface of the first voice coil bobbin 21 , and the inner edge 27 a of the first damper 27 and the first voice coil bobbin 21 are connected via the coupler 23 . That is, the connection between the diaphragm 24 and the first voice coil bobbin 21 and the connection between the first damper 27 and the first voice coil bobbin 21 are realized through the coupler 23 . Therefore, compared with a method in which the diaphragm 24 and the first voice coil bobbin 21 are connected and the first damper 27 and the first voice coil bobbin 21 are connected at different positions in the front-back direction, the speaker 10 can be made thinner.

[0075] In this embodiment, the inner edge 24a of the vibration plate 24 is located radially inward of the inner edge 27a of the first damper 27. Therefore, the first vibrating portion 20 including the coupler 23, the vibration plate 24, and the first damper 27 can be assembled easily.

[0076] In addition, in this embodiment, Figure 4 As shown in FIG. 2 , the coupler 23 has a recess 23 b corresponding to the position where the transmission path is to be arranged. Therefore, the arrangement of the transmission path is easy.

[0077] In addition, in this embodiment, Figure 4 As shown, the coupler 23 is formed with a conductive relay member 23 c as an embedded part. Therefore, the relay member 23 c embedded in the coupler 23 can relay the transmission path connected to the first coil 22 and the transmission path connected to the outside of the speaker 10.

[0078] In addition, in this embodiment, Figure 1 As shown, the first vibrating portion 20 has an edge 25 that elastically supports the outer edge 24b of the vibration plate 24. The outer edge 27b of the first damper 27 is located radially outward of the outer edge 24b of the vibration plate 24. Therefore, first damper 27 is located behind outer edge 24b of diaphragm 24, thereby suppressing interference between outer edge 24b of diaphragm 24 and other components. Therefore, the distance between diaphragm 24 and first damper 27 in the front-to-back direction can be set small, allowing speaker 10 to be thinner.

[0079] However, since the first damper 27 and the second damper 37 are displaced in opposite directions, the volume of the space between the first damper 27 and the second damper 37 inside the speaker 10 varies significantly.

[0080] Therefore, in this embodiment, the frame 50 has a second opening 59B (see FIG. 5B ) that connects the space between the first damper 27 and the second damper 37 inside the speaker 10 and the space outside the speaker 10. Figure 7 ). Therefore, the air in the space between the first damper 27 and the second damper 37 inside the speaker 10 can be released.

[0081] In addition, in this embodiment, Figure 1As shown, the coupler 23 includes a vertical wall portion 65 that contacts the inner edge portion 24a of the vibration plate 24. Therefore, the vertical wall portion 65 of the coupler 23 serves as a guide, and the vibration plate 24 can be arranged at a desired position relative to the coupler 23. In addition, in this embodiment, the magnetic circuit 40 includes a first magnet 42, a second magnet 44, a first magnetic member 41 mounted on the first magnet 42, a second magnetic member 45 mounted on the second magnet 44, and an intermediate magnetic member 43 mounted between the first magnet 42 and the second magnet 44. The intermediate magnetic member 43 forms a first magnetic gap G1 between the first magnetic member 41 and the intermediate magnetic member 43, and forms a second magnetic gap G2 between the intermediate magnetic member 43 and the second magnetic member 45. Therefore, the intermediate magnetic member 43 can be used as a path for both the magnetic flux passing through the first magnetic gap G1 and the magnetic flux passing through the second magnetic gap G2 , and the thickness of the magnetic circuit 40 can be reduced.

[0082] Furthermore, in this embodiment, the second vibrating portion 30 includes a weight 39. Therefore, compared to an embodiment in which the second vibrating portion 30 does not include a weight 39, the amplitude of the second vibrating portion 30 can be reduced while maintaining the effect of canceling out the vibration of the entire loudspeaker 10. Consequently, the loudspeaker 10 can be made thinner.

[0083] Furthermore, in this embodiment, the second voice coil bobbin 31 protrudes forward (upward) relative to the counterweight 39. In other words, the counterweight 39 does not protrude forward relative to the second voice coil bobbin 31. Therefore, compared to, for example, a configuration in which the counterweight 39 is hooked onto the front end of the second voice coil bobbin 31, it is easier to reduce the thickness of the loudspeaker 10.

[0084] In this embodiment, second damper 37 includes two elastic bodies 37A and 37B. This improves the symmetry and straightness of movement of second vibrating portion 30 during vibration. Furthermore, counterweight 39 is positioned between the two elastic bodies 37A and 37B. Therefore, counterweight 39 does not adversely affect the thinness of speaker 10.

[0085] In addition, in this embodiment, Figure 6 As shown, the weight 39 has a recessed portion 39a in a portion of the circumference thereof to increase the distance between the weight 39 and the second voice coil bobbin 31. Therefore, when welding the outer circumference of the second voice coil bobbin 31, the recessed portion 39a is provided corresponding to the welded portion, thereby preventing short circuits between the second voice coil bobbin 31 and the weight 39 caused by solder slag, other metal components, and the like.

[0086] In addition, in this embodiment, Figure 3As shown, the second damper 37 includes a first elastic body 37A integrated with the transmission path (ribbon wiring 82). Therefore, no space is required for the transmission path, which contributes to a reduction in the thickness of the speaker 10.

[0087] (Second embodiment) Figure 8 A speaker 110 according to a second embodiment is shown.

[0088] In the second embodiment, the structure of the second vibrating portion 130 is different from the second vibrating portion 30 of the first embodiment. The second vibrating portion 130 includes a second damper 137. The second damper 137 comprises a first elastic body 137A and a second elastic body 37B, which are arranged so as to overlap in the vibration direction. Furthermore, the first elastic body 37A has a recessed portion 37A1 that is recessed in the direction toward the second elastic body 37B in the vibration direction. The counterweight 139 is located on the surface of the recessed portion 37A1 opposite the second elastic body 37B. This eliminates the need to place the counterweight 39 between the first elastic body 137A and the second elastic body 37B, and can suppress any increase in the size of the second vibrating portion 30 in the amplitude direction.

[0089] [Supplementary explanation] While the preferred embodiments of the present invention have been described in detail above, the present invention is not limited to the above embodiments.

[0090] The materials of each part of the first vibrating part 20 and the second vibrating part 30, 130 are not particularly limited. For example, the vibration plate 24, the first damper 27, the elastomers 37A, 37B and the cover 26 can use various materials such as paper, resin, metal, or a composite material obtained by combining these, and ceramic. Moreover, the edge 25 can use a polymer material with relatively high elasticity, such as rubber and resin. In addition, as a material of each part of the first vibrating part 20 and the second vibrating part 30, 130, a fiber material can also be used. Furthermore, the base material of each component of the first vibrating part 20 and the second vibrating part 30, 130 can also be coated with a rubber coating or the like. The frame 50 and the spacer 38 can use a resin, paper, metal non-magnetic material, etc.

[0091] The diameter and thickness of each member shown in each drawing are examples, and the member is not limited to this shape and size.

[0092] In the above embodiment, an example in which the coupler 23 is joined to one elastic body (elastic body 27A) has been described, but the present disclosure is not limited thereto and the coupler may be joined to two or more elastic bodies. Furthermore, in the above embodiment, an example in which the vibration plate 24 and the first damper 27 are joined to the coupler 23 has been described. However, the coupler may be further joined to another member (for example, a cover).

[0093] In the above embodiment, the recess 23b is formed at a position corresponding to the entire transmission path provided in the coupler 23. However, the recess of the present disclosure is not limited thereto. The recess may be formed at least partially at the position where the transmission path is provided. In addition, when a relay member is provided in the coupler, the coupler does not need to have a recessed portion.

[0094] In the above embodiment, an example in which the conductive relay member 23c is molded as an insert in the coupler 23 has been described, but the relay member of the present disclosure is not limited thereto. The relay member may be held in the coupler by a method other than insert molding.

[0095] In addition, the structure of the counterweight 39 is not limited to the above-mentioned embodiment. For example, a weight can be attached to the inner circumference of the voice coil bobbin. Alternatively, a counterweight can be attached to the front end of the voice coil bobbin. Furthermore, the shape of the weight is not limited to annular; for example, it can be polygonal or have a cutout. Furthermore, the counterweight does not need to have a recess. Furthermore, the weight can be insulated from the voice coil.

[0096] In addition, the structure of the second damper 37 is not limited to the above-mentioned embodiment. For example, the elastic body of the second damper may be one, or three or more. In addition, the spacer 38 may not be provided, and two elastic bodies may be mounted on the frame by providing a step on the frame.

[0097] Figure 9 It is a perspective view showing a counterweight 239 according to a modified example.

[0098] The counterweight 239 is generally annular (specifically, generally circular), but is arc-shaped and notched at one portion of the circumference. That is, the counterweight 239 is generally annular with a notch 39b at a portion of the circumference.

[0099] The weight 239 is made of a metal material, and is composed of a non-magnetic material such as aluminum.

[0100] The counterweight 239 has a recess 39a. The counterweight 239 has the recess 39a, and the distance between the inner peripheral surface of the counterweight 239 and the outer peripheral surface of the second voice coil bobbin 31 is increased in a portion of the circumference where the recess 39a is formed. The recess 39a is formed in the inner connecting portion 82a (see FIG. 1 ) including the two ribbon wirings 82. Figure 3) is connected to the transmission path formed on the outer peripheral surface of the second voice coil bobbin 31. The position where the recess 39a is provided is a position on the opposite side of the notch 39b across the central axis O1 of the speaker 10 (the center of the vibration axis of the second vibrating part 30).

[0101] The dimensions of the cutout 39b are set so that the center of gravity of the counterweight 239 is located on the central axis O1 of the loudspeaker 10. Specifically, the cutout 39b is formed on the opposite side of the recess 39a across the central axis O1. Therefore, by appropriately setting the dimensions of the cutout 39b, the center of gravity of the counterweight 239 can be brought close to the central axis O1. This allows the center of gravity of the weight 239 to be approximately aligned with the central axis O1 of the loudspeaker 10. In other words, the center of gravity of the weight 239 can be approximately aligned with the central axis of the second vibrating part 30, thereby suppressing the roll of the second vibrating part 30 and ensuring the straightness of the vibration of the second vibrating part 30. The approximate alignment of the center of gravity of the counterweight 239 with the central axis of the second vibrating part 30 (the central axis O1 of the loudspeaker 10) is permitted to a degree that does not interfere with the amplitude motion of the second vibrating part 30.

[0102] In addition, Figure 9 In the illustrated example, the outer peripheral surface 73 and the inner peripheral surface 74 of the weight 239 extend in an arc shape centered on the central axis O1 of the speaker 10 .

[0103] Next, the effects of the modified example will be described.

[0104] Manufacturing speaker 10 requires a process (hereinafter referred to as a magnetizing process) of magnetizing second magnet 44 included in magnetic circuit 40 . The magnetizing process may be performed while magnetic circuit 40 and second vibrating part 30 are assembled to frame 50 . Here, assuming that the weight 239 is completely annular, during the magnetization process, current flows in a circular shape in the weight 239 to generate a force, and an unnecessarily strong force acts on the weight 239 . Therefore, in this modification, the weight 239 has a notch 39 b. Therefore, during the magnetization process, the current is prevented from flowing through the counterweight 239 in a circular shape, and a strong force is prevented from acting on the counterweight 239.

[0105] In this modification, the weight 239 is made of a metal material. Therefore, it is easy to ensure the mass of the weight 239 and the driving force of the second vibrating part 30.

[0106] Furthermore, if the weight 239 is made of a magnetic material such as iron, the weight 239 receives an unnecessary force from the magnetic field generated by the magnetic circuit 40 . Therefore, in this modification, the weight 239 is made of a non-magnetic material such as aluminum. Therefore, it is possible to prevent the weight 239 from receiving an unnecessary force from the magnetic field generated by the magnetic circuit 40 .

[0107] The disclosure of Japanese Patent Application No. 2023-004734 filed on January 16, 2023 is incorporated herein by reference in its entirety. Description of reference numerals:

[0108] 10 speakers 20First vibration part 21First voice coil frame 22 first coil 23 coupler 23a Avoidance 23b concave part 23c Relay Component 24 vibration plates 24a inner edge 24b outer edge 25 Edge 27 First Damper 27a inner edge 27b outer edge 30 Second vibration part 31 Second voice coil frame 32 Second coil 37 Second damper 37A first elastic body 37B second elastic body 39 counterweight 39a recess 39b incision 40 magnetic circuit 50 frames 59B second opening (opening) 65 second vertical wall portion (vertical wall portion) 82 strip wiring (wiring) 110 speakers 130 second vibration part 137 Second damper 137A first elastic body 139 counterweight 239 counterweight G1 first magnetic gap G2 second magnetic gap O1 center axis

Claims

1. A loudspeaker comprising: magnetic circuit; a first vibrating portion that vibrates to generate sound and includes a first voice coil bobbin, a first coil, a first damper, and a vibration plate; and The second vibrating part vibrates to cancel the vibration of the entire speaker caused by the first vibrating part, and includes a second voice coil bobbin, a second coil, a second damper, and a weight. The magnetic circuit has: First magnet; a first magnetic member mounted on the first magnet; a first magnetic yoke mounted on the first magnet to form a first magnetic gap with the first magnetic member; as well as a second magnetic yoke forming a second magnetic gap with the first magnetic yoke, The counterweight is composed of a conductor as a non-magnetic member. The weight has a substantially annular shape with a cutout in a portion of its circumference. 2 . The speaker according to claim 1 , wherein the second voice coil bobbin protrudes upward relative to the weight.

3. The loudspeaker according to claim 1, wherein the second damper comprises two elastic bodies. The counterweight is configured between the two elastic bodies.

4. The speaker according to claim 1, wherein the second damper includes a first elastic body and a second elastic body arranged to overlap in a vibration direction. The first elastic body has a concave portion that is concave in a direction approaching the second elastic body in the vibration direction. The weight is disposed on a surface of the recessed portion on the opposite side to the second elastic body.

5. The speaker according to claim 1, wherein the weight is arranged so as to surround the second voice coil bobbin. The weight has a recessed portion in a portion of its circumference for increasing the distance between the weight and the second voice coil bobbin. The speaker according to claim 5 , wherein the center of gravity of the weight is substantially the same as the central axis of the second vibrating part. 7 . The speaker according to claim 1 , wherein the second damper includes an elastic body integrated with a wiring.

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