Patent Translate Powered by EPO and Google Notice This translation is machine-generated. It cannot be guaranteed that it is intelligible, accurate, complete, reliable or fit for specific purposes. Critical decisions, such as commercially relevant or financial decisions, should not be based on machine-translation output. DESCRIPTION JP2008028749 The present invention provides a speaker capable of satisfactorily adjusting the magnetic flux density of a magnetic gap with a simple configuration, and a method of manufacturing a magnetic circuit portion of the speaker. A first magnetic path (A1) passing through a substantially annular first magnetic gap (G1) by a magnet (210) and a first pole (220) and a second yoke (230) for inducing magnetic flux from the magnet (210). And a second magnetic path A2 passing through a second magnetic gap G2 provided on the outer diameter side of the first magnetic gap G1, the speaker 100 having the first and second magnetic gaps G1, G2 The area S3 substantially orthogonal to the magnetic flux of the first pole 220 is set so that the magnetic flux density to be generated has a predetermined size, and the ratio of the magnitudes of the magnetic flux density generated in the first and second magnetic gaps G1 and G2 The area ratio of the areas S1 and S2 substantially orthogonal to the magnetic flux of the first and second body parts 232B and 233B is set so that the ratio of the predetermined size becomes a ratio of the predetermined size. [Selected figure] Figure 1 Speaker and method of manufacturing speaker magnetic circuit [0001] The present invention relates to a speaker having a plurality of magnetic gaps, and a method of manufacturing a speaker magnetic circuit unit. [0002] Conventionally, a speaker having a plurality of magnetic gaps is known (see, for example, Patent Document 1 and Patent Document 2). 02-05-2019 1 [0003] According to Patent Document 1, a magnet, an annular plate fixed to one surface of the magnet, a pole piece for fixing the other surface of the magnet, and a space between the pole piece and the outer plate And an inner plate disposed. In this speaker, an annular inner plate is disposed so that an outer gap is formed on the inner side of the outer plate, and a rod-like member protruding from the disc-like portion of the pole piece is the inner gap between the rod-like member and the inner surface of the inner plate. Are arranged to be formed. And in this speaker, the thickness of the inner peripheral side of an inner side plate is made thicker than the thickness of an outer side plate, and the composition which makes the magnetic flux density of an inner side gap larger than the magnetic flux density of an outer side gap is taken. [0004] Moreover, the thing of the patent document 2 is a magnetic circuit for composite type speakers which consists of a magnet, a pole piece, and a yoke. In this magnetic circuit, an annular upper yoke is disposed on one surface of a magnet, a disc-shaped lower yoke is disposed on the other surface of the magnet, and a disc of the lower yoke is disposed between the upper yoke and the inner surface of the upper yoke. The pole pieces are disposed and formed so as to form magnetic gaps respectively with the rod-like parts projecting from the parts. A high conductivity and magnetoresistive element are disposed between the pole piece and the lower yoke, and the magnetic flux density in the magnetic gap is adjusted by changing the magnetic resistance of the magnetic circuit passing from the pole piece to the lower yoke. There is. [0005] Japanese Utility Model Application Publication No. 53-163121 Japanese Utility Model Application Publication No. 55-100391 [0006] 02-05-2019 2 By the way, in the conventional speaker like patent document 1, since the thickness of the inner peripheral side of an inner side plate is thicker than the thickness of an outer side plate, the magnetic flux density in an outer side gap can be made larger than the magnetic flux density of an inner side gap However, it is difficult to cope with the case where the magnetic flux density of the inner gap is made larger than the magnetic flux density of the outer gap. Also, since two magnetic gaps are provided in one magnetic circuit, the magnetic fluxes passing through the respective magnetic gaps are substantially equal, and it is possible to minutely change the magnetic flux density of each magnetic gap, but There is a problem that it can not cope with the case where the magnetic flux density in the gap is largely different. [0007] Moreover, in patent document 2, it is necessary to prepare separately a high magneticconductivity body and a magnetic resistance body, and the problem that the number of parts increases and a structure becomes complexity is mentioned. [0008] In view of the problems as described above, it is an object of the present invention to provide a speaker having a magnetic gap with an appropriate magnetic flux density and a method of manufacturing a speaker magnetic circuit section with a simple configuration. [0009] The invention according to claim 1 includes a magnet and a magnetic body for inducing a magnetic flux formed between mutually opposing poles of the magnet, and the magnet and the magnetic body form a substantially annular first magnetic gap. The first magnetic path passing through, the first magnetic gap, and the substantially annular second magnetic gap provided on the outer diameter side of the first magnetic gap, and the second magnetic gap on the inner diameter side of the first magnetic gap It is a speaker provided with the speaker magnetic circuit part in which the 2nd magnetic path provided with the common magnetic path which shares a part of one magnetic path, and forming, and forming a part of the common magnetic path, A common magnetic body side magnet contact surface which is in contact with one end surface of the magnet, a common magnetic body side gap forming surface which faces the first magnetic gap, and the common magnetic body side magnet contact surface and the common magnetic body side gap forming surface Common magnetism to connect A common magnetic body having a body portion, and a substantially cylindrical shape standing at a plate-like bottom portion in 02-05-2019 3 contact with the other end surface of the magnet at a predetermined distance from the common magnetic body, and the common magnetic body side A first magnetic gap forming surface which forms the first magnetic gap facing the gap forming surface, a common magnetic path forming portion which forms a part of the common magnetic path, and a second magnetic flux path forming portion connected to the common magnetic path forming portion A first magnetic body comprising: a first magnetic body-side second magnetic gap forming surface facing the magnetic gap; and a first body portion branched from the common magnetic path to form a circuit other than the common magnetic path of the first magnetic path The first magnetic body and the second magnetic gap are formed in a substantially cylindrical shape in a state of being separated from the first magnetic body by a predetermined dimension in a plate-like bottom portion in contact with the body and the other end face of the magnet A second magnetic field facing the surface to form the second magnetic gap A second magnetic body having a cap forming surface, and a second body portion branched from the common magnetic path to form a circuit other than the common magnetic path of the second magnetic path, the first magnetic gap, and the second magnetic body According to another aspect of the present invention, there is provided a speaker including: a coil portion provided in each of the magnetic gaps; and a diaphragm connected to the coil portion to vibrate by vibration of the coil portion. [0010] The invention according to claim 4 includes a magnet and a magnetic body for inducing a magnetic flux formed between mutually opposing poles of the magnet, and the magnet and the magnetic body form a substantially annular first magnetic gap. The first magnetic path passing through, the first magnetic gap, and the substantially annular second magnetic gap provided on the outer diameter side of the first magnetic gap, and the second magnetic gap on the inner diameter side of the first magnetic gap It is a speaker provided with the speaker magnetic circuit part in which the 2nd magnetic path provided with the common magnetic path which shares a part of one magnetic path, and the magnetic circuit part, and the magnet has one end face and the other end face mutually counter Are formed in a substantially cylindrical shape to form a part of the common magnetic path, and a common magnetic body side magnet contact surface which is in contact with one end face of the magnet, and a common magnetic body side which faces the first magnetic gap A gap forming surface, and the common magnetic body A common magnetic body section connecting a magnet contact surface and the common magnetic material side gap forming surface is provided, and the area substantially orthogonal to the magnetic flux of the common magnetic path is the magnetic flux density of the first magnetic gap and the second magnetic gap. It faces the common magnetic body whose area is set to a desired size, the first magnet contact surface which is in contact with the other end face of the magnet, and the common magnetic material side gap forming surface of the common magnetic body. A first magnetic gap forming surface that forms one magnetic gap, a common magnetic path forming portion that forms a part of the common magnetic path, and a first magnetic body side that continuously opposes the second magnetic gap to the common magnetic path forming portion A 02-05-2019 4 first magnetic body comprising a second magnetic gap forming surface, and a first body connecting the first magnet abutting surface and the first magnetic gap forming surface, and a second magnet abutting on the other end surface of the magnet Abutment surface, said first magnetic body side second magnetic gap forming surface A second magnetic gap forming surface facing the second magnetic gap and a second body connecting the second magnetic contact surface and the second magnetic gap forming surface, the first magnetic gap and the second magnetic gap According to the ratio of the magnetic flux density to the magnetic gap, at least one of the area ratio between the first magnet contact surface and the second magnet contact surface and the area ratio between the first body and the second body A second magnetic body of which one is set, a coil portion provided in each of the first magnetic gap and the second magnetic gap, and a diaphragm connected to the coil portion and vibrated by the vibration of the coil portion , And a speaker characterized in that. [0011] The invention according to claim 11 includes a magnet and a magnetic body for inducing a magnetic flux formed between mutually opposing poles of the magnet, and the magnet and the magnetic body form a substantially annular first magnetic gap. The first magnetic path passing through, the first magnetic gap, and the substantially annular second magnetic gap provided on the outer diameter side of the first magnetic gap, and the second magnetic gap on the inner diameter side of the first magnetic gap A method of manufacturing a speaker magnetic circuit portion in which a second magnetic path provided with a common magnetic path sharing a part of one magnetic path is formed, the magnetic flux generated in the first magnetic gap and the second magnetic gap The area substantially orthogonal to the magnetic flux of the magnetic members constituting the common magnetic path is set so that the density becomes a desired size, and the magnitude of the magnetic flux density generated in the first magnetic gap and the second magnetic gap The ratio is The area substantially orthogonal to the magnetic flux of the magnetic substance constituting the circuit other than the common magnetic path of the first magnetic path and the common magnetic path of the second magnetic path so as to obtain the desired size ratio. A method of manufacturing a speaker magnetic circuit portion characterized in that the magnetic body is formed by setting the area ratio of the area substantially orthogonal to the magnetic flux of the magnetic body constituting the circuit of (1). [0012] First Embodiment A loudspeaker according to a first embodiment of the present invention will be described below based on the drawings. 02-05-2019 5 FIG. 1 is a side sectional view showing an outline of a speaker according to a first embodiment. FIG. 2 is a view schematically showing a magnetic path of the speaker magnetic circuit unit in the first embodiment. In addition, although a cone-type speaker is illustrated in the present embodiment, the present invention is not limited to this. [0013] [Speaker Configuration] In FIG. 1, reference numeral 100 denotes a speaker, and the speaker 100 outputs by sound an audio signal which is an electrical signal from a playback device (not shown) electrically connected. The speaker 100 includes a magnetic circuit unit 200 as a speaker magnetic circuit unit, a frame unit 300, a diaphragm 400, and the like. [0014] The magnetic circuit unit 200 includes a magnet 210, a first pole 220 as a magnetic body, and a second yoke 230 as a magnetic body. [0015] The magnet 210 is formed in a substantially cylindrical shape, and the upper end surface is in contact with the first pole 220, and the lower end surface is in contact with the second yoke 230, and fixed by, for example, an adhesive. Here, the magnet 210 is formed such that the upper end surface in contact with the first pole 220 is the N pole, and the lower end surface in contact with the second yoke 230 is the S pole. In the present embodiment, the magnet 210 whose upper end face is N pole and whose lower 02-05-2019 6 end face is S pole is exemplified, but the present invention is not limited thereto. For example, the upper end face is formed of S pole and the lower end face is formed of N pole It is good also as composition. [0016] The first pole 220 is formed in a substantially cylindrical shape and disposed coaxially with the magnet 210. The first pole 220 is formed of, for example, a magnetic member capable of favorably inducing a magnetic flux such as iron. At the lower end side of the first pole 220, a magnet contact portion 221 as a common magnetic body body to be in contact with the magnet 210 is provided. Further, on the upper end side of the first pole 220, a magnetic gap forming portion 222 which is formed to protrude in the circumferential direction is provided. The magnetic gap forming portion 222 opposes the second yoke 230 with a predetermined distance dimension and is provided with a common magnetic material side gap forming surface which forms the first magnetic gap G1. [0017] The second yoke 230 includes a bottom portion 231 which constitutes a part of the common magnetic body, an inner annular portion 232 as a first magnetic body and an outer annular portion 233 as a second magnetic body, which rise from the bottom portion 231. The bottom portion 231, the inner annular portion 232, and the outer annular portion 233 are integrally formed of, for example, a magnetic member such as iron that can favorably induce a magnetic flux. In the present embodiment, an example in which the bottom portion 231, the inner annular portion 232, and the outer annular portion 233 are integrally formed is shown, but for example, they are separately provided and adhered and fixed by an adhesive or welding. The configuration may be [0018] The bottom portion 231 is formed in a substantially disc shape coaxial with the magnet 210. The lower end surface of the magnet 210 is in contact with the upper surface of the bottom portion 231 and fixed by, for example, an adhesive. Here, the upper surface diameter dimension of the bottom portion 231 is formed larger than the diameter dimension of the lower end surface of the magnet 210, and the entire lower end surface of the magnet 210 is fixed in a state where it abuts 02-05-2019 7 on the upper surface of the bottom portion 231. [0019] The inner annular portion 232 is provided with a substantially cylindrical first body portion 232B which is coaxial with the magnet 210 and rises in a direction substantially parallel to the axial direction of the magnet 210 from the upper surface of the bottom portion 231. An inner circumferential surface of the first body portion 232B of the inner annular portion 232 is formed apart from the outer circumferential surface of the magnet 210 and the outer circumferential surface of the first pole 220 by a predetermined dimension. A first magnetic gap forming surface 232A projecting to the inner peripheral side is formed on the upper end side of the first body portion 232B. A first magnetic gap G1 is formed between the first magnetic gap 222 and the common magnetic body side gap formation surface. In addition, a first magnetic body-side second magnetic gap forming surface (not shown) is provided on a part of the outer peripheral surface facing the outer annular portion 233 of the first trunk portion 232B that faces the second magnetic gap forming surface 233A described later. It is formed. Furthermore, a common magnetic path forming portion is formed between the first magnetic gap forming surface 232A and the first magnetic body-side second magnetic gap forming surface at the upper end portion of the first body portion 232B. [0020] The outer annular portion 233 includes a substantially cylindrical second body portion 233B which rises from the upper surface of the bottom portion 231 in a direction substantially parallel to the axial direction of the magnet 210 along the outer peripheral edge of the bottom portion 231. The second body 233B is formed such that the inner circumferential surface thereof is separated from the outer circumferential surface of the inner annular portion 232 by a predetermined dimension. A second magnetic gap forming surface 233A protruding toward the inner annular portion 232 is formed at the upper end of the second body 233B. The second magnetic gap forming surface 233A and the outer periphery of the first body 232B. A second magnetic gap G2 is formed between it and the surface. [0021] Here, the distance dimension between the common magnetic material side gap forming surface of the first pole 220 and the first magnetic gap forming surface 232A of the inner annular portion 232, that is, the gap length of the first magnetic gap G1 The distance dimension between 02-05-2019 8 the one magnetic body-side second magnetic gap forming surface and the second magnetic gap forming surface 233A of the outer annular portion 233, that is, the gap length of the second magnetic gap G2 is formed shorter. [0022] Further, the area of the common magnetic material side gap forming surface of the first pole 220 and the area of the first magnetic gap forming surface 232A of the inner annular portion 232 are formed smaller than the area of the second magnetic gap forming surface 233A of the outer annular portion 233 There is. That is, the gap width substantially orthogonal to the magnetic flux in the first magnetic gap G1 is formed narrower than the gap width substantially orthogonal to the magnetic flux in the second magnetic gap G2. [0023] In such a magnetic circuit unit 200, as shown in FIG. 2, a first magnetic path A1 and a second magnetic path A2 are formed. The first magnetic path A1 passes from the N pole of the magnet 210, the first pole 220, the first magnetic gap G1, the inner annular portion 232 of the second yoke 230, and the bottom 231 to the S pole of the magnet 210. It is a magnetic circuit to return. On the other hand, the second magnetic path A2 passes from the N pole of the magnet 210, the first pole 220, the first magnetic gap G1, the upper end of the inner annular portion 232, and the second magnetic gap G2. Then, the magnetic circuit returns to the S pole of the magnet 210 from the bottom portion 231 through the outer annular portion 233 of the second yoke 230. That is, the second magnetic path A2 is a magnetic circuit branched from the first magnetic path A1, and is branched at a common magnetic path forming portion provided at the upper end portion of the inner annular portion 232 in the first magnetic path A1. A magnetic circuit in which magnetic flux flows from the portion 232 to the bottom 231 is the first magnetic path A1, and a magnetic circuit passing through the second magnetic gap G2 is the second magnetic path A2. Therefore, from the magnetic circuit section from the magnet 210 through the first pole 220 to the first magnetic gap G1 to the upper end of the inner annular portion 232, and from the connection position between the bottom portion 231 and the inner annular portion 232 A magnetic circuit section from the bottom 231 to the return to the magnet 210 is a common magnetic path A3 in the first magnetic path A1 and the second magnetic path A2. 02-05-2019 9 [0024] At this time, the cross-sectional area S3 substantially orthogonal to the magnetic flux in the magnet contact portion 221 of the first pole 220 constituting the common magnetic path A3 is based on the amount of magnetic flux flowing through the first magnetic path A1 and the second magnetic path A2. Is set. Here, the cross-sectional area S3 is substantially proportional to the amount of magnetic flux flowing through the first magnetic path A1 and the second magnetic path A2. Therefore, for example, when the amount of magnetic flux flowing through the first magnetic path A1 and the second magnetic path A2 is reduced, the cross-sectional area S3 is also set to be small in proportion to the amount of magnetic flux. On the other hand, when the amount of magnetic flux flowing through the first magnetic path A1 and the second magnetic path A2 is increased, the cross-sectional area S3 is also set substantially in proportion to the amount of magnetic flux. [0025] In addition, the cross-sectional area S1 substantially orthogonal to the magnetic flux of the first trunk portion 232B of the inner annular portion 232 constituting the first magnetic path A1, and the second trunk portion of the outer annular portion 233 constituting the second magnetic path A2. The cross-sectional area S2 substantially orthogonal to the magnetic flux of 233B is set based on the ratio of the amount of magnetic flux passing through the first magnetic path A1 and the second magnetic path A2. Here, the cross-sectional area S1 and the cross-sectional area S2 substantially coincide with the ratio of the amount of magnetic flux passing through the first magnetic path A1 and the second magnetic path A2. Therefore, for example, when increasing the ratio of the amount of magnetic flux flowing through the first body portion 232B in the ratio of the amount of magnetic flux flowing through the first body portion 232B and the second body portion 233B, the ratio of the amount of magnetic flux The cross-sectional area S1 of the first body 232B and the cross-sectional area S2 of the second body 233B are set so that the ratio of the cross-sectional area S1 in the area ratio of the cross-sectional area S1 and the cross-sectional area S2 is correspondingly increased. On the other hand, when the ratio of the amount of magnetic flux flowing through the first body portion 232B is reduced in the ratio of the amount of magnetic flux flowing through the first body portion 232B and the second body portion 233B, the ratio of the amount of magnetic flux Then, the cross-sectional area S1 of the first body 232B and the cross-sectional area S2 of the second body 233B are set such that the ratio of the crosssectional area S1 in the area ratio of the cross-sectional area S1 and the cross-sectional area S2 decreases. 02-05-2019 10 [0026] Therefore, by appropriately setting the cross-sectional area S1 of the first body 232B, the crosssectional area S2 of the second body 233B, and the cross-sectional area S3 of the magnet contact portion 221, the first magnetic path A1 and the second magnetic path The amount of magnetic flux passing through A2 is set, and the magnetic flux density of the first magnetic gap G1 and the second magnetic gap G2 is set. [0027] The frame unit 300 includes an outer frame 310 and an inner frame 320. [0028] The outer frame 310 has an outer frame bottom 312 in which a substantially circular opening 311 is formed substantially at the center of the bottom surface. On the outer peripheral edge of the outer frame bottom portion 312, a plurality of outer bridge portions 313 are provided in a substantially radial manner in a state where the outer bridge portions 313 expand at the tip end side. In addition, a first mounting step 314 is provided in the vicinity of the outer frame bottom 312 of the outer bridge 313. Furthermore, at the tip of the outer cross-linking portion 313, a second mounting stepped portion 315 substantially in a ring shape and substantially parallel to the outer frame bottom portion 312 is provided. A positioning cylindrical portion 316 formed in a substantially cylindrical shape is provided in series on the outer peripheral edge of the second mounting stepped portion 315. And the terminal which is not shown in figure which has a terminal into which the audio ¦ voice signal of an electrical signal is input is attached to the flame ¦ frame part 300 integrally. [0029] The inner frame 320 has a substantially cylindrical inner frame bottom portion 321 provided on the upper surface side of the inner annular portion 232 of the second yoke 230 of the magnetic circuit unit 200. On one end side in the axial direction of the inner frame bottom portion 321, a 02-05-2019 11 plurality of inner bridge portions 322 are provided in a substantially radial manner in a state where the inner bridge portions 322 expand at the tip end side. A substantially ring-shaped inner attachment portion 323 is provided at the tip of the inner bridge portion 322. At the outer peripheral edge of the inner attachment portion 323, a positioning portion 324 formed in a substantially cylindrical shape is provided. [0030] The diaphragm 400 includes an outer diaphragm 410 and an inner diaphragm 420. [0031] The outer diaphragm 410 is formed substantially in the form of a thin film, for example, a magnesium thin plate whose surface has been subjected to corrosion-proof treatment, a titanium alloy, paper pulp, or sheet members of various fibers. The outer diaphragm 410 has a substantially cone-shaped outer vibrating portion 411 which spreads toward one side. An outer edge portion 412 is adhesively fixed to the outer peripheral edge of the outer vibrating portion 411 by, for example, an adhesive in order to hold the outer vibrating portion 411. Further, the outer peripheral edge of the outer edge portion 412 is adhesively fixed to the mounting surface of the second mounting stepped portion 315 of the outer frame 310 by, for example, an adhesive. Further, on the inner peripheral edge of the outer vibration portion 411, an outer attachment portion 414 formed in a series of substantially cylindrical shapes is provided. The outer attachment portion 414 is a diameter dimension of the second magnetic gap G2 of the magnetic circuit portion 200, that is, an outer circumferential surface of the inner annular portion of the second yoke 230 from the axis of the magnet 210 and a second magnetic gap formation of the outer annular portion. It is formed in the cylindrical shape of the diameter dimension substantially the same as the diameter dimension to the approximate center position vicinity of surface 233A. Although FIG. 1 shows an example in which the outer edge portion 412 is provided as a separate member from the outer vibrating portion 411 and bonded and fixed, for example, the outer edge portion 412 may be integrally formed with the outer vibrating portion 411. [0032] Further, an outer voice coil bobbin 510 is integrally provided on the outer diaphragm 410. The 02-05-2019 12 outer voice coil bobbin 510 includes a substantially cylindrical outer coil bobbin 511 and an outer voice coil 512 as a coil portion. [0033] The outer coil bobbin 511 is formed of, for example, a metal material, a resin material, or the like in a substantially cylindrical shape. The outer coil bobbin 511 has a diameter substantially the same as the diameter of the outer attachment portion 414 of the outer diaphragm 410, and one end thereof is fixed to the outer attachment portion 414 in the axial direction by, for example, an adhesive. The other axial end of the outer coil bobbin 511 is inserted through the second magnetic gap G2 of the magnetic circuit unit 200 so as not to contact the inner annular portion 232 and the outer annular portion 233 of the second yoke 230. The outer coil bobbin 511 may be integrally provided, for example, by adhesion with an adhesive to a spherical dome-shaped dust cap closing the end face on one end side of the side where the outer diaphragm 410 is expanded. . [0034] The outer voice coil 512 is wound on the outer peripheral surface on the other end side in the axial direction of the outer coil bobbin 511 so as to be inserted into the second magnetic gap G2. The outer voice coil 512 is configured by winding a conductive wire coated with an insulating layer, for example, around the outer coil bobbin 511. The lead of the outer voice coil 512 is connected to the terminal of a terminal (not shown) provided on the outer frame 310, and an audio signal is input from the terminal. [0035] Further, the outer voice coil bobbin 510 is integrally provided with a substantially disc-shaped attachment support portion 600 which is a so-called damper. And, as shown in FIG. 1, the mounting support portion 600 is substantially cylindrical with the outer coil bobbin 511 inserted at substantially the center, and the inner peripheral surface thereof is integrally formed on the outer peripheral surface of the outer coil bobbin 511 with, for example, an adhesive. It has a cylindrical part which is not shown attached. Furthermore, the mounting support portion 600 is provided with a series of movable portions 610 that are formed in a radial direction at one end in the axial direction of the cylindrical portion, and are formed in a corrugated shape along the 02-05-2019 13 radial direction. Further, at the outer peripheral edge of the movable portion 610, there is provided a hook portion 620 which protrudes in a hook shape and is attached to the first mounting stepped portion 314 of the outer frame 310 by, for example, an adhesive. The flange 620 of the attachment support 600 is attached to the first attachment step 314 of the outer frame 310, and the outer diaphragm support 413 of the outer edge 412 of the outer diaphragm 410 is attached to the second attachment of the outer frame 310. By being attached to the step portion 315, the outer diaphragm 410 to which the outer voice coil bobbin 510 is integrally attached is disposed on the outer frame 310. In this disposed state, the outer voice coil 512 is located in the second magnetic gap G2. [0036] Similar to the outer diaphragm 410, the inner diaphragm 420 is formed substantially in the form of a thin film, for example, a magnesium thin plate whose surface has been subjected to corrosion-proof treatment, a titanium alloy, paper pulp, or sheet members of various fibers. The inner diaphragm 420 has a substantially cone-shaped inner vibrating portion 421 which spreads toward one side. On the outer peripheral edge of the inner vibrating portion 421, an inner edge portion 422 bent in a substantially U-shaped cross section is continuously formed in a state of projecting in the same direction as the side where the inner vibrating portion 421 spreads. The inner vibrating portion 421 may be separately provided on the edge portion 422, and may be integrally fixed by, for example, bonding and fixing with an adhesive or the like. Further, an inner diaphragm supporting portion 423 protruding outward like a hook is provided on the outer peripheral edge of the inner edge portion 422, and the inner diaphragm supporting portion 423 is attached to the inner attachment portion 323 of the inner frame 320. The surface is adhesively fixed, for example, by an adhesive. In addition, a spherical dome-shaped dust cap 424 is integrally provided on the inner peripheral edge of the inner vibrating portion 421 in a state of closing the opening. Furthermore, an inner voice coil bobbin 520 is integrally provided on the inner peripheral edge of the inner vibrating portion 421. [0037] The inner voice coil bobbin 520 is provided with a substantially cylindrical inner coil bobbin 521 and an inner voice coil 522 as a coil portion. Similar to the outer coil bobbin 511, the inner coil bobbin 521 is formed in a substantially cylindrical shape, for example, of a metal material, a resin material, or the like. The inner coil bobbin 521 has an outer diameter substantially equal to the inner diameter of the inner peripheral edge of the inner diaphragm 420, and one end in the axial direction is fixed to the inner diameter of the inner diaphragm 420 by, for example, an adhesive. . 02-05-2019 14 Further, the other axial end of the inner coil bobbin 521 is inserted in the first magnetic gap G1 of the magnetic circuit unit 200 so as not to contact the outer peripheral edge of the first pole 220 and the inner annular portion 232 of the second yoke 230. ing. [0038] The inner voice coil 522 is wound on the outer peripheral surface on the other axial end side of the inner coil bobbin 521 so as to be inserted into the first magnetic gap G1. The inner voice coil 522 is configured by winding a conductive wire coated with an insulating layer, for example, around the inner coil bobbin 521. The lead of the inner voice coil 522 is connected to the terminal of a terminal (not shown) provided on the frame unit 300, and an audio signal is input from the terminal. [0039] The inner diaphragm support portion 423 of the inner diaphragm 420 is attached to the inner attachment portion 323 of the inner frame 320, whereby the inner diaphragm 420 to which the inner voice coil bobbin 520 is integrally attached is disposed on the inner frame 320. Be done. In this disposed state, the inner voice coil 522 is located in the first magnetic gap G1. [0040] [Method of Manufacturing Speaker] Next, a method of manufacturing the above-described speaker 100 will be described. The magnetic flux density in the first magnetic gap G1 and the second magnetic gap G2 of the magnetic circuit unit 200 is an important factor in determining the performance of the speaker 100, and the magnetic flux of these first and second magnetic gaps G1, G2 The size of the density is adjusted by the shapes of the first pole 220 and the second yoke 230. [0041] Specifically, first, the cross-sectional area S1 of a portion of the inner annular portion 232 of the second yoke 230 which is substantially orthogonal to the magnetic flux of the first body portion 02-05-2019 15 232B and the magnetic flux of the second body portion 233B of the outer annular portion 233 are substantially orthogonal. The cross-sectional area S2 of the portion to be adjusted is adjusted in accordance with the magnitude of the magnetic flux density generated in the first and second magnetic gaps G1, G2. That is, the magnetic flux flowing through both the first magnetic path A1 and the second magnetic path A2 passes through the first magnetic gap G1, and only the magnetic flux flowing through the second magnetic path A2 passes through the second magnetic gap G2. . Therefore, by adjusting the area ratio of the cross-sectional area S1 of the inner annular portion 232 and the cross-sectional area S2 of the outer annular portion, the amount of magnetic flux flowing to the inner annular portion 232 after passing through the first magnetic gap G1, It is possible to adjust the amount of magnetic flux flowing through the outer annular portion 233 through the magnetic gap G2. For example, when the cross-sectional area S1 of the first body portion 232B of the inner annular portion 232 is made larger than the cross-sectional area S2 of the second body portion 233B of the outer annular portion 233, the amount of magnetic flux flowing through the inner annular portion 232 is increased. The amount of magnetic flux flowing to the outer annular portion 233 is reduced. As a result, the magnetic flux density in the second magnetic gap G2 decreases, and the magnetic flux density in the second magnetic gap can be reduced. On the other hand, when the cross-sectional area S1 of the first barrel 232B of the inner annular portion 232 is smaller than the cross-sectional area S2 of the second barrel 233B of the outer annular portion 233, the amount of magnetic flux flowing through the inner annular portion 232 decreases. The amount of magnetic flux flowing to the outer annular portion 233 is increased. Thereby, the magnetic flux density in the second magnetic gap G2 can be increased, and the magnetic flux density of the second magnetic gap can be increased. [0042] Furthermore, the total of the magnetic flux flowing through the first magnetic path A1 and the second magnetic path A2 is adjusted by adjusting the cross-sectional area S3 substantially orthogonal to the magnetic flux of the magnet contact portion 221 of the first pole 220 constituting the common magnetic path A3. Adjust the amount of That is, when the crosssectional area S3 substantially orthogonal to the magnetic flux of the magnet contact portion 221 is reduced, the magnetic flux hardly flows in the common magnetic path A3, and the amount of magnetic flux flowing in the first magnetic path A1 and the second magnetic path A2 decreases. . Thereby, the magnetic flux density in the first magnetic gap G1 and the second magnetic gap G2 also decreases. On the other hand, when the cross-sectional area S3 of the magnet contact portion 221 is increased, the amount of magnetic flux flowing through the common magnetic path A3 increases, so the amount of magnetic flux flowing through the first magnetic path A1 and the second magnetic path A2 also increases. Therefore, the magnetic flux density in the first magnetic gap G1 and the second magnetic gap G2 also increases. 02-05-2019 16 [0043] As described above, the cross-sectional area S3 substantially orthogonal to the magnetic flux of the magnet contact portion 221, the cross-sectional area S1 substantially orthogonal to the magnetic flux of the first barrel 232B, and the cross-sectional area substantially orthogonal to the magnetic flux of the second barrel 233B. By adjusting S2 appropriately, the magnetic flux density of the first magnetic gap G1 and the second magnetic gap G2 is adjusted to a magnetic flux density of a desired size. [0044] Thereafter, the frame unit 300 is fixed to the magnetic circuit unit 200. Then, the inner voice coil bobbin 520 and the inner diaphragm 420 are disposed such that the inner voice coil 522 is disposed in the first magnetic gap G1, and the inner diaphragm support portion 423 is attached to the inner attachment portion 323 of the inner frame 320. Further, the electric wire of the inner voice coil 522 is electrically connected to the terminal of the frame portion 300. [0045] Similarly, the outer voice coil bobbin 510 and the outer diaphragm 410 are disposed such that the outer voice coil 512 is disposed in the second magnetic gap G2, and the outer diaphragm support 413 of the outer diaphragm 410 is It is attached to the second attachment step 315, and the flange 620 of the attachment support 600 is attached to the first attachment step 314. Also, the end of the outer voice coil 512 is connected to the terminal of the frame section 300. Thus, the speaker 100 is assembled and manufactured. [0046] [Function and Effect of Speaker] In the speaker 100 as described above, the first magnetic path A1 is formed by the magnet 210, the first pole 220, and the inner annular portion 232 of the second yoke 230, and the magnet 210, the first pole 220. The second magnetic path A2 is formed by the outer annular portion 233 of the second yoke 230, and the magnet 210 from the 02-05-2019 17 bottom portion 231 of the second yoke 230 among the first magnetic path A1 and the second magnetic path A2 is a first pole A common magnetic path A3 is formed across the tip of the inner annular portion 232 of the second yoke 230 at 220. The cross-sectional area S3 of the portion of the first pole 220 substantially orthogonal to the magnetic flux of the magnet contact portion 221 is set according to the amount of magnetic flux flowing from the magnet 210 to the common magnetic path A3. The cross-sectional area S1 of a portion of the inner annular portion 232 of the second yoke 230 which is substantially orthogonal to the magnetic flux of the first body portion 232B and the magnetic flux of the second body portion 233B of the outer annular portion 233 of the second yoke 230 are substantially orthogonal. The area ratio of the sectional area S2 of the portion is the total magnetic flux passing through the first magnetic gap G1, the amount of magnetic flux in the first magnetic path A1 branched from the inner annular portion 232 to the bottom 231, and the second magnetic gap G2 It is set according to the ratio to the amount of magnetic flux in the second magnetic path A2 that passes through and branches from the outer annular portion 233 to the bottom portion 231. Therefore, the amount of magnetic flux flowing through each of the first magnetic path A1 and the second magnetic path A2 can be set appropriately, and the magnetic flux density in the first magnetic gap G1 and the second magnetic gap G2 can also be set appropriately. can do. Therefore, the diaphragm 400 of the speaker 100 can be vibrated more appropriately, and a good sound can be output. In the manufacturing method of manufacturing the magnetic circuit unit 200 of the speaker 100, the cross section S3 of the portion of the first pole 220 substantially orthogonal to the magnetic flux of the magnet contact portion 221 and the inner annular portion of the second yoke 230 An area ratio of a cross-sectional area S1 of a portion substantially orthogonal to the magnetic flux of the first barrel 232B and a cross-sectional area S2 of a portion substantially orthogonal to the magnetic flux of the second barrel 233B of the outer annular portion 233 of the second yoke 230; Is adjusted as appropriate. Therefore, by adjusting the cross-sectional area S3 of the portion substantially orthogonal to the magnetic flux of the magnet contact portion 221, the amount of magnetic flux flowing from the magnet 210 to the common magnetic path A3 can be adjusted. Further, by adjusting the area ratio of the cross-sectional area S1 of the first body 232B and the cross-sectional area S2 of the second body 233B, the inner annular portion 232 to the bottom 231 of all the magnetic flux passing through the first magnetic gap G1. It is possible to adjust the amount of magnetic flux in the first magnetic path A1 to branch to and the amount of magnetic flux in the second magnetic path A2 to branch from the outer annular portion 233 to the bottom portion 231 through the second magnetic gap G2. . Therefore, the magnetic flux density in the first magnetic gap G1 and the second magnetic gap G2 can be easily adjusted by appropriately adjusting the amount of magnetic flux flowing through each of the first magnetic path A1 and the second magnetic path A2. Can. In addition, there is no need to separately provide a magnetic resistance member or the like for adjusting the magnetic flux density of the first and second magnetic gaps G1 and G2, and the first and second yokes 220 and 230 only have the first and second shapes. Since the magnetic flux density of the 02-05-2019 18 magnetic gaps G1 and G2 can be adjusted, the configuration can be simplified and the manufacturing efficiency can also be improved. [0047] The common magnetic path A3 is a section from the vicinity of the inner annular portion 232 in the bottom portion 231 of the second yoke 230 to the magnet 210, the magnet 210, the first pole 220, and the first magnetic gap G1. Is formed in the section leading to the upper end of the inner annular portion 232. That is, the common magnetic path A3 is provided on the inner diameter side of the first magnetic gap G1, and the second magnetic gap G2 having a smaller magnetic flux density than the first magnetic gap G1 is formed on the outer diameter side of the first magnetic gap G1. There is. Therefore, even the small-diameter inner diaphragm 420 can be sufficiently vibrated, and a better sound can be output, for example, when the inner diaphragm 420 generates a sound in a high sound area. [0048] The positions of the first pole 220, the inner annular portion 232, and the outer annular portion 233 are set such that the gap length of the first magnetic gap G1 is shorter than the gap length of the second magnetic gap G2. Furthermore, the common magnetic material side gap forming surface, the first magnetic gap forming surface 232A, and the second magnetic gap forming surface 233A are formed such that the gap width of the first magnetic gap G1 is narrower than the gap width of the second magnetic gap G2. ing. Therefore, the magnetic flux density of the first magnetic gap G1 can be made sufficiently larger than the magnetic flux density of the second magnetic gap G2. Therefore, for example, in the case where the sound of the high sound area is generated from the inner diaphragm 420 and the sound of the low sound area is generated from the outer diaphragm 410, a good sound can be output from each diaphragm 400. [0049] Furthermore, the second yoke 230 can be easily manufactured since the bottom portion 231, the inner annular portion 232, and the outer annular portion 233 are integrally formed. [0050] Further, as described above, since the magnetic flux densities of the first magnetic gap G1 and 02-05-2019 19 the second magnetic gap G2 in the magnetic circuit unit 200 are properly adjusted, in the speaker 100 provided with the magnetic circuit unit 200, the outer diaphragm The 410 and the inner diaphragm 420 can be appropriately vibrated according to the magnetic flux density of the first magnetic gap G1 and the second magnetic gap G2. [0051] Second Embodiment Next, a loudspeaker 100A according to a second embodiment of the present invention will be described based on the drawings. FIG. 3 is a side sectional view of the speaker according to the second embodiment. FIG. 4 is a view schematically showing a magnetic path of the speaker magnetic circuit unit of the second embodiment. In FIGS. 3 and 4, the same components as those in the first embodiment are given the same reference numerals, and the description thereof will be omitted or simplified. [0052] [Speaker Configuration] In FIG. 3, the speaker 100A of the second embodiment includes a magnetic circuit unit 200A as a speaker magnetic circuit unit, a frame unit 300, a diaphragm 400, and the like. In the speaker 100A according to the second embodiment, the configurations of the frame 300, the diaphragm 400, the voice coil bobbins 510 and 520, and the mounting support 600 are the same as those in the first embodiment, as described above. The explanation is omitted. [0053] As shown in FIG. 2, the magnetic circuit unit 200A of the speaker 100A includes a magnet 210A, a lower yoke 240 as a common magnetic body, a first upper yoke 250 as a first magnetic body, and a second magnetic body. And a second upper yoke 260. [0054] The magnet 210A is formed in a ring shape, and for example, the upper end surface is an S pole and the lower end surface is an N pole. 02-05-2019 20 [0055] The lower yoke 240 is formed of, for example, a magnetic member capable of favorably inducing a magnetic flux such as iron. The lower yoke 240 includes a bottom portion 241 and a cylindrical portion 242 as a common magnetic body trunk portion rising from the substantially central position of the bottom portion 241 to the upper surface side. The bottom portion 241 is formed in a substantially disc shape, a common magnetic body magnet contact surface is formed on the upper surface side of the bottom portion 241, and the lower end surface of the magnet 210A is in contact and fixed. The cylindrical portion 242 is formed to rise on the upper surface side of the bottom portion 241 on the axial center of the magnet 210A. Further, on the upper end side of the cylindrical portion 242, a common magnetic material side gap forming surface 243 is formed as a common magnetic material gap forming surface which protrudes in the radial direction and is continuous in the circumferential direction. The common magnetic material side gap forming surface 243 faces the first upper yoke 250 to form a first magnetic gap G1. [0056] Similar to the lower yoke 240, the first upper yoke 250 is formed of, for example, a magnetic member capable of favorably inducing a magnetic flux such as iron. The first upper yoke 250 includes a substantially cylindrical first body 250A. At a lower end portion of the first body 250A, a first magnet contact surface 251 is formed to be in contact with the upper end surface of the magnet 210A. Further, a first magnetic gap forming surface 252 is formed on the upper end portion of the first body 250A so as to protrude in the circumferential direction on the inner peripheral side. The first magnetic gap forming surface 252 is opposed to the common magnetic material side gap forming surface 243 of the lower yoke 240 by a predetermined dimension and is opposed to the common magnetic material side gap forming surface 243 as described above. A magnetic gap G1 is formed. In addition, on the outer peripheral surface facing the second upper yoke 260 of the first upper yoke 250, the first magnetic body-side second magnetic gap forming surface (not shown) is provided on a part facing the second magnetic gap forming surface 262 described later. Is formed. Further, a common magnetic path forming portion is formed between 02-05-2019 21 the first magnetic gap forming surface 252 and the first magnetic material side second magnetic gap forming surface at the upper end portion of the first upper yoke. [0057] Similar to the lower yoke 240 and the first upper yoke 250, the second upper yoke 260 is formed of, for example, a magnetic member capable of favorably inducing a magnetic flux such as iron. The second upper yoke 260 includes a substantially cylindrical second body 260A in which the diameter of the inner peripheral surface is larger than the diameter of the outer peripheral surface of the first upper yoke 250. The second body 260A is disposed such that the inner circumferential surface thereof is separated from the outer circumferential surface of the first upper yoke 250 by a predetermined dimension. Further, at the lower end portion of the second body portion 260A, a second magnet contact surface 261 which is in contact with the upper end surface of the magnet 210A is formed. Further, on the upper end side of the second body portion 260A, a second magnetic gap forming surface 262 which protrudes to the inner peripheral side and is continuous in the circumferential direction is formed. The second magnetic gap forming surface 262 is opposed to the outer peripheral surface of the first barrel 250A of the first upper yoke 250 with a predetermined size open to form a second magnetic gap G2. [0058] Here, the distance dimension between the common magnetic material side gap forming surface 243 of the lower yoke 240 and the first magnetic gap forming surface 252 of the first upper yoke 250, that is, the gap length of the first magnetic gap G1 is the first upper yoke A distance dimension between the first magnetic body-side second magnetic gap forming surface 250 and the second magnetic gap forming surface 262 of the second upper yoke 260 is formed shorter than the gap length of the second magnetic gap G2. [0059] Furthermore, the areas of the common magnetic material side gap formation surface 243 of the lower yoke 240 and the first magnetic gap formation surface 252 of the first upper yoke 250 are the same as the first magnetic material second magnetic gap formation surface of the first upper yoke 250 and the The area is smaller than the area of the second magnetic gap forming surface 262 of the two upper yokes 260. 02-05-2019 22 That is, the gap width substantially orthogonal to the magnetic flux in the first magnetic gap G1 is formed narrower than the gap width substantially orthogonal to the magnetic flux in the second magnetic gap G2. [0060] In such a magnetic circuit unit 200A, as shown in FIG. 4, a first magnetic path A1 and a second magnetic path A2 are formed. The first magnetic path A1 passes from the N pole of the magnet 210A through the bottom portion 241 of the lower yoke 240 and the cylindrical portion 242, passes through the first magnetic gap G1, passes through the first upper yoke 250, and returns to the S pole of the magnet 210A. It is a magnetic circuit. On the other hand, the second magnetic path A2 passes the first magnetic gap G1 from the N pole of the magnet 210A, the bottom portion 241 of the lower yoke 240, the cylindrical portion 242, the upper end portion of the first upper yoke 250, Further, it is a magnetic circuit that passes through the second magnetic gap G2, passes through the second upper yoke 260, and returns to the S pole of the magnet 210A. That is, the magnetic circuit which branches at the upper end portion of the first upper yoke 250 in the first magnetic path A1 and in which the magnetic flux flows in the first upper yoke 250 is the first magnetic path A1 and passes through the second magnetic gap G2. Is the second magnetic path A2. Therefore, the magnetic circuit section from the magnet 210A to the lower yoke 240, and the first magnetic gap G1 to the upper end of the first upper yoke 250 is the first magnetic path A1 and the second magnetic path. It becomes a common magnetic path A3 in the path A2. [0061] At this time, the contact area S4 of the bottom 241 of the lower yoke 240 constituting the common magnetic path A3 with the magnet 210A is based on the desired amount of magnetic flux flowing through the first magnetic path A1 and the second magnetic path A2. It is set. Here, the contact area S4 is substantially proportional to the amount of magnetic flux flowing through the first magnetic path A1 and the second magnetic path A2. Therefore, for example, in the case of reducing the amount of magnetic flux flowing through the first magnetic path A1 and the second magnetic path A2, the amount of magnetic flux flowing through the first magnetic path A1 and the second magnetic path A2 is also the contact area S4. The ratio is set to be approximately in proportion to. On the other hand, when the amount of magnetic flux flowing through the first magnetic path A1 and the second magnetic path A2 is increased, the contact area S4 is also set to be large in proportion to the amount of magnetic flux. 02-05-2019 23 [0062] In addition, the area S5 of the first magnet contact surface 251 in contact with the magnet 210A of the first upper yoke 250 constituting the first magnetic path A1, and the second upper yoke 260 magnet 210A constituting the second magnetic path A2 The area S6 of the second magnet contact surface 261 in contact is set based on the ratio of the desired amount of magnetic flux passing through the first magnetic path A1 and the second magnetic path A2. Here, the area S5 of the first magnet abutment surface 251 and the area S6 of the second magnet abutment surface 261 are of magnetic flux passing through portions other than the common magnetic path A3 in the first magnetic path A1 and the second magnetic path A2. It substantially corresponds to the ratio of the quantities. Therefore, for example, in the ratio of the amount of magnetic flux passing through the portion other than the common magnetic path A3 in the first magnetic path A1 and the second magnetic path A2, the magnetic flux flowing in the portion other than the common magnetic path A3 in the first magnetic path A1 When the ratio of the amounts is increased, the area S5 in the area ratio of the area S5 of the first magnet abutting surface 251 to the area S6 of the second magnet abutting surface 261 corresponding to the ratio of the desired amount of the magnetic flux The area S5 of the first magnet abutment surface 251 and the area S6 of the second magnet abutment surface 261 are set so that the ratio is large. On the other hand, in the ratio of the amount of magnetic flux passing through the portion other than the common magnetic path A3 in the first magnetic path A1 and the second magnetic path A2, the amount of magnetic flux flowing in the portion other than the common magnetic path A3 in the first magnetic path A1 The ratio of the area S5 in the area ratio of the area S5 of the first magnet abutment surface 251 to the area S6 of the second magnet abutment surface 261 is small corresponding to the ratio of the amount of magnetic flux Thus, the area S5 of the first magnet abutment surface 251 and the area S6 of the second magnet abutment surface 261 are set. [0063] Thereby, the contact area S4 of the bottom portion 241 with the magnet 210A, the contact area S5 of the first magnet contact surface 251 with the magnet 210A, and the contact area S6 of the second magnet contact surface 261 with the magnet 210A are appropriate By setting to, the amount of magnetic flux passing through the first magnetic path A1 and the second magnetic path A2 is set, and the magnetic flux density of the first magnetic gap G1 and the second magnetic gap G2 is set. [0064] 02-05-2019 24 [Method of Manufacturing Speaker] Next, a method of manufacturing the above speaker 100A will be described. The magnetic flux density in the first magnetic gap G1 and the second magnetic gap G2 of the magnetic circuit unit 200A is an important factor in determining the performance of the speaker 100, and the magnetic flux of these first and second magnetic gaps G1, G2 The size of the density is adjusted by the shapes of the first upper yoke 250 and the second upper yoke 260. [0065] Specifically, first, the contact area S5 of the first magnet contact surface 251 of the first upper yoke 250 and the magnet 210A, and the contact area of the second magnet contact surface 261 of the second upper yoke 260 and the magnet 210A. The contact area S6 is adjusted in accordance with the magnitude of the magnetic flux density generated in the first and second magnetic gaps G1, G2. That is, the magnetic flux flowing through both the first magnetic path A1 and the second magnetic path A2 passes through the first magnetic gap G1, and only the magnetic flux flowing through the second magnetic path A2 passes through the second magnetic gap G2. . Therefore, the first magnetic gap G1 is adjusted by adjusting the area ratio of the contact area S5 between the first magnet contact surface 251 and the magnet 210A and the contact area S6 between the second magnet contact surface 261 and the magnet 210A. The amount of magnetic flux flowing through the first upper yoke 250 and the amount of magnetic flux flowing through the second upper yoke 260 through the second magnetic gap G2 can be adjusted. For example, when the contact area S5 between the first magnet contact surface 251 and the magnet 210A is larger than the contact area S6 between the second magnet contact surface 261 and the magnet 210A, the magnetic flux flowing in the first upper yoke 250 The amount of magnetic flux flowing through the second upper yoke 260 is reduced. Thereby, the magnetic flux density in the second magnetic gap G2 is reduced. On the other hand, when the contact area S5 between the first magnet contact surface 251 and the magnet 210A is smaller than the contact area S6 between the second magnet contact surface 261 and the magnet 210A, the magnetic flux flowing in the first upper yoke 250 The amount of magnetic flux flowing through the second upper yoke 260 is increased. Thereby, the magnetic flux density in the second magnetic gap G2 is increased. [0066] Furthermore, the total amount of magnetic flux flowing through the first magnetic path A1 and 02-05-2019 25 the second magnetic path A2 is adjusted by adjusting the contact area S4 between the bottom portion 241 of the lower yoke 240 forming the common magnetic path A3 and the magnet 210A. Do. That is, when the contact area S4 of the lower yoke 240 with the magnet 210A is reduced, the magnetic flux hardly flows in the common magnetic path A3, and the amount of magnetic flux flowing in the first magnetic path A1 and the second magnetic path A2 decreases. Thereby, the magnetic flux density in the first magnetic gap G1 and the second magnetic gap G2 also decreases, and the magnetic flux density also decreases. On the other hand, if the contact area S4 of the lower yoke 240 with the magnet 210A is increased, the amount of magnetic flux flowing through the common magnetic path A3 increases, so the amount of magnetic flux flowing through the first magnetic path A1 and the second magnetic path A2 Also increases. Thereby, the magnetic flux density in the first magnetic gap G1 and the second magnetic gap G2 also increases. [0067] As described above, the first magnetic gap G1 and the second magnetic gap G1 can be adjusted by appropriately adjusting the contact areas S4, S5 and S6 of the lower yoke 240, the first upper yoke 250, and the second upper yoke 260 with the magnet 210A. The magnetic flux density of the magnetic gap G2 is adjusted to a desired magnetic flux density. [0068] Thereafter, the frame unit 300 is fixed to the magnetic circuit unit 200A. Then, the inner voice coil bobbin 520 and the inner diaphragm 420 are disposed such that the inner voice coil 522 is disposed in the first magnetic gap G1, and the inner diaphragm support portion 423 is attached to the inner attachment portion 323 of the inner frame 320. Further, the electric wire of the inner voice coil 522 is electrically connected to the terminal of the frame portion 300. [0069] Similarly, the outer voice coil bobbin 510 and the outer diaphragm 410 are disposed such that the outer voice coil 512 is disposed in the second magnetic gap G2, and the outer diaphragm support 413 of the outer diaphragm 410 is It is attached to the second attachment step 315, and the flange 620 of the attachment support 600 is attached to the first attachment step 314. Also, 02-05-2019 26 the end of the outer voice coil 512 is connected to the terminal of the frame section 300. Thus, the speaker 100 is assembled and manufactured. [0070] [Operation and Effect of Speaker] In the speaker 100A as described above, in the magnetic circuit unit 200A, the first magnetic path A1 is formed by the magnet 210A, the lower yoke 240, and the first upper yoke 250, and the magnet 210A, the lower side. A second magnetic path A2 is formed by the yoke 240 and the second upper yoke 260, and from the lower yoke 240 of the first magnetic path A1 and the second magnetic path A2 to the upper end portion of the first upper yoke 250. Thus, a common magnetic path A3 is formed. The contact area S4 of the bottom portion 241 of the lower yoke 240 with the magnet 210A is set according to the desired amount of magnetic flux flowing from the magnet 210A to the common magnetic path A3. The area ratio of the contact area S5 of the first magnet contact surface 251 with the magnet 210A and the contact area S6 of the second magnet contact surface 261 with the magnet 210A is the total magnetic flux passing through the first magnetic gap G1. Of the magnetic flux in the first magnetic path A1 returning to the magnet 210A through the first upper yoke 250, and the second magnetic flux passing through the second magnetic gap G2 and returning to the magnet 210A through the second upper yoke 260. It is set according to the desired ratio to the amount of magnetic flux in the path A2. Therefore, as in the first embodiment, the amount of magnetic flux flowing through each of the first magnetic path A1 and the second magnetic path A2 can be appropriately set, and the first magnetic gap G1 and the second magnetic path can be set. The ratio of the magnetic flux density to the gap G2 can also be set appropriately. Therefore, the diaphragm 400 of the speaker 100A can be vibrated more appropriately, and a good sound can be output. [0071] In the manufacturing method of manufacturing such a magnetic circuit unit 200A, the contact area S4 of the bottom portion 241 of the lower yoke 240 with the magnet 210A, the first magnet contact surface 251 of the first upper yoke 250, and the magnet 210A. And the area ratio of the contact area S6 between the second magnet contact surface 261 of the second upper yoke 260 and the magnet 210A. Therefore, by adjusting the contact area S4 of the bottom portion 241 with the magnet 210A, the amount of magnetic flux flowing from the magnet 210A to the common magnetic path A3 can be adjusted. Further, by adjusting the area ratio of the contact area S5 of the first magnet contact surface 251 with the magnet 210A and the contact area S6 of the second magnet contact surface 261 with the magnet 210A, the first magnetic gap G1 can be 02-05-2019 27 obtained. The amount of magnetic flux in the first magnetic path A1 returned to the magnet 210A through the first upper yoke 250 out of the total magnetic flux passed through the second upper yoke 260 through the second magnetic gap G2 to the magnet 210A The amount of magnetic flux in the returning second magnetic path A2 can be adjusted. Therefore, the magnetic flux density in the first magnetic gap G1 and the second magnetic gap G2 can be easily adjusted by appropriately adjusting the amount of magnetic flux flowing through each of the first magnetic path A1 and the second magnetic path A2. . Further, it is not necessary to separately provide a magnetic resistance member or the like for adjusting the magnetic flux density of the first and second magnetic gaps G1 and G2, and the lower yoke 240, the first upper yoke 250, and the second upper yoke 260 are not provided. Since the magnetic flux density of the first and second magnetic gaps G1 and G2 can be adjusted only by the contact area with the magnet 210A, the configuration can be simplified and the manufacturing efficiency can be improved. [0072] Further, as in the first embodiment, the common magnetic path A3 is formed in a section from the lower yoke 240 to the upper end portion of the first upper yoke 250 through the first magnetic gap G1. That is, the common magnetic path A3 is provided on the inner diameter side of the first magnetic gap G1, and the second magnetic gap G2 having a smaller amount of magnetic flux than the first magnetic gap G1 is formed on the outer diameter side of the first magnetic gap G1. ing. Therefore, even the small-diameter inner diaphragm 420 can be sufficiently vibrated, and a better sound can be output, for example, when the inner diaphragm 420 generates a sound in a high sound area. [0073] Also, the positions of the lower yoke 240, the first upper yoke 250, and the second upper yoke 260 are set such that the gap length of the first magnetic gap G1 is shorter than the gap length of the second magnetic gap G2. . Furthermore, the common magnetic material side gap forming surface 243, the first magnetic gap forming surface, and the second magnetic gap forming surface 262 are formed such that the gap width of the first magnetic gap G1 is narrower than the gap width of the second magnetic gap G2. ing. Therefore, as in the first embodiment, the magnetic flux density of the first magnetic gap G1 can be made sufficiently larger than the magnetic flux density of the second magnetic gap G2. Therefore, for example, in the case where the sound of the high sound area is generated from the inner diaphragm 420 and the sound of the low sound area is generated from the outer diaphragm 410, a good sound can be output from each diaphragm 400. 02-05-2019 28 [0074] Further, as in the first embodiment, since the magnetic flux density of the first magnetic gap G1 and the second magnetic gap G2 in the magnetic circuit unit 200A is appropriately adjusted, the speaker provided with the magnetic circuit unit 200A. In 100A, the outer diaphragm 410 and the inner diaphragm 420 can be appropriately vibrated according to the magnetic flux density of the first magnetic gap G1 and the second magnetic gap G2. [0075] [Other Embodiments] The present invention is not limited to the above-described embodiment, and includes the following modifications as long as the object of the present invention can be achieved. [0076] For example, separate magnets may be provided on both of the first upper yoke 280 and the magnet 210 and between the second upper yoke 290 and the magnet 210, respectively. In this case, the magnetic flux density of the first magnetic gap G1 and the second magnetic gap G2 can be set in more detail by providing magnets having different magnetic forces. [0077] A magnetic circuit unit 200D of the speaker 100D in FIG. 5 includes a magnet 210, a second magnet 210C, a third magnet 210D, a lower yoke 234 as a magnetic body, and a first upper yoke 235 as a common magnetic body. And a second upper yoke 236 as a second magnetic body. The magnet 210 is formed in a substantially cylindrical shape as in the above embodiment, and for example, the magnet 210 is disposed so that the upper surface side is an N pole and the lower surface side is an S pole. The magnet 210 is fixed in contact with the first upper yoke 235 on the upper surface side, and fixed in contact with the lower yoke 234 on the lower surface side. The second magnet 210C is formed in a substantially ring shape, and is disposed, for example, such that the upper surface side is an S pole and the lower surface side is an N pole. 02-05-2019 29 The second magnet 210C is fixed in contact with the second upper yoke 236 on the upper surface side, and fixed in contact with the lower yoke 234 on the lower surface side. The third magnet 210D is formed in a substantially ring shape, and is disposed, for example, such that the upper surface side is an N pole. The third magnet 210D is fixed in contact with the lower yoke 234 on the upper surface side. [0078] The lower yoke 234 is provided with a bottom portion 234A constituting a part of a substantially disc-shaped common magnetic body, and an annular portion 234B as a first magnetic body rising from the outer peripheral edge of the bottom portion 234A ing. A magnet 210 coaxial with the annular portion 234B is in contact with the top surface of the bottom portion 234A at a position separated from the inner circumferential surface of the annular portion 234B by a predetermined dimension. In addition, the second magnet 210C is in contact with the upper surface side of the bottom portion 234A along the outer peripheral edge. Further, the third magnet 210D is in contact with the lower surface side of the bottom portion 234A along the outer peripheral edge. The annular portion 234B includes a first body 234C disposed at a predetermined distance from the outer peripheral surface of the magnets 210 and 210C so as not to contact the magnet 210 and the second magnet 210C. A first magnetic gap forming surface 234D which protrudes to the inner diameter side and is continuous in the circumferential direction is formed at the upper end side tip end portion of the first body portion 234C. The first upper yoke 235 is provided with a cylindrical portion 235A as a substantially cylindrical common magnetic body barrel. At a lower end portion of the cylindrical portion 235A, a magnet contact surface 235B as a common magnetic body side magnet contact surface to be in contact with the magnet 210 is formed. In addition, a gap forming surface 235C which protrudes to the outer diameter side and is continuous in the circumferential direction is formed at the upper end side tip end of the cylindrical portion 235A, and the first magnetic gap G1 faces the first magnetic gap forming surface 234D. Form The second upper yoke 236 includes a substantially cylindrical second body 236A. At a lower end portion of the second body portion 236A, a second magnet contact surface 236B that is in contact with the upper surface of the second magnet 210C is formed. In addition, a second magnetic gap forming surface 236C which protrudes to the inner diameter side and is continuous in the circumferential direction is formed at the upper end side tip end portion of the second body portion 236A. Two magnetic gaps G2 are formed. [0079] Here, as in the above embodiment, the gap length of the first magnetic gap G1 is formed shorter than the gap length of the second magnetic gap G2, and the gap width of the first magnetic gap G1 is the second magnetic gap G2. It is formed narrower than the gap width of. 02-05-2019 30 [0080] In the magnetic circuit unit 200D as described above, as shown in FIG. 6, a first magnetic path A1 and a second magnetic path A2 are formed. The first magnetic path A1 passes through the first upper yoke 235 and the first magnetic gap G1 from the N pole of the magnet 210, and returns to the S pole of the magnet 210 from the annular portion 234B of the lower yoke 234 through the bottom 234A. It is a circuit. The second magnetic path A2 passes from the N pole of the magnet 210, the first upper yoke 235, the first magnetic gap G1, the tip of the annular portion 234B of the lower yoke 234, and the second magnetic gap G2. It is a magnetic circuit that passes from the second upper yoke 236 through the second magnet 210C and the bottom 234A of the lower yoke 234 and returns to the S pole of the magnet 210. In the magnetic circuit portion 200D, the magnetic circuit section from the bottom portion 234A to the magnet 210, the first upper yoke 235, and the first magnetic gap G1 to the top end of the annular portion 234B of the lower yoke 234 The first magnetic path A1 and the second magnetic path A2 become a common magnetic path A3. Further, since the second magnetic path portion A2 of the magnetic circuit portion 200D passes through the magnet 210 and the second magnet 210C, the magnetic flux density is increased. Further, since the N pole of the second magnet 210C and the N pole of the third magnet 210D are disposed opposite to the lower yoke 234 with the bottom 234A interposed therebetween, the magnetic flux density at the bottom 234A of the second magnetic path A2 is further increased. growing. Therefore, the magnetic flux density of the first magnetic gap G1 and the second magnetic gap G2 can be further increased. Thus, by using a plurality of magnets, the magnetic flux density of one of the first magnetic gap G1 and the second magnetic gap G2 can be made larger, or the magnetic flux density of both magnetic gaps can be made larger. Can be [0081] The magnetic circuit unit 200D of such a speaker 100D is also manufactured in the same manner as the first embodiment. That is, the area ratio between the cross-sectional area S1 substantially orthogonal to the magnetic flux of the first barrel 234C of the annular portion 234B and the cross-sectional area S2 substantially orthogonal to the magnetic flux of the second barrel 236A of the second upper yoke 236 is appropriately adjusted. Thus, the magnitude of the magnetic flux density of the second magnetic gap G2 with respect to the first magnetic gap G1 is adjusted. Further, by adjusting the cross-sectional area S3 substantially orthogonal to the magnetic flux of 02-05-2019 31 the cylindrical portion 235A of the first upper yoke 235, the amount of magnetic flux flowing to the common circuit portion A3 is adjusted, that is, the first magnetic gap G1 and the second magnetic The magnitude of the magnetic flux density of the gap G2 is adjusted. [0082] In the above embodiment, the magnetic circuit units 200, 200A, 200D are formed to have a substantially circular cross section, and the outer peripheral edge of the diaphragm 400 of the speakers 100, 100A, 100D is formed in a circular cone shape. Although used, for example, the magnetic circuit portion may be formed to have a substantially elliptical cross section, and the diaphragm may be configured to have the outer peripheral edge formed to have a substantially elliptical shape accordingly. [0083] Furthermore, in the above embodiment, the configuration in which the two magnetic gaps of the first magnetic gap G1 and the second magnetic gap G2 are provided is exemplified, but for example, in the magnetic circuit portion of the speaker in which three or more magnetic gaps are formed. It may be. Even in such a case, the size of the magnetic flux density in each magnetic gap is adjusted by adjusting the area ratio of the cross-sectional area substantially orthogonal to the magnetic flux in each magnetic circuit section branched after passing through each magnetic gap can do. [0084] Further, in the first embodiment, the cross-sectional area S3 substantially orthogonal to the magnetic flux of the magnet contact portion 221 of the first pole 220 is appropriately adjusted, and in the second embodiment, the bottom portion 241 of the lower yoke 240 The magnitude of the magnetic flux density of the first magnetic gap G1 and the second magnetic gap G2 is adjusted by appropriately adjusting the contact area S4 with the magnet 210A in the above, but the invention is not limited thereto. For example, the amount of magnetic flux of the first magnetic path A1 and the second magnetic path A2 may be adjusted by appropriately adjusting the area of the common magnetic material side gap forming surface in the magnetic gap forming portion 222. Even in this case, the area ratio of the cross section orthogonal to the magnetic flux of the first body 232B and the cross section orthogonal to the magnetic flux of the second body 02-05-2019 32 233B is set to the desired size of the magnetic flux density in the first magnetic gap G1 and the second magnetic gap G2. The magnetic flux density in the first magnetic gap G1 and the second magnetic gap G2 can be adjusted by adjusting according to the ratio of the heights. In the first embodiment, as in the second embodiment, the first magnetic path A1 and the second magnetic path A2 are adjusted by adjusting the contact area between the first pole 220 and the magnet 210. It is good also as composition adjusted the amount of all the magnetic flux in. Similarly, in the second embodiment, the amount of total magnetic flux in the first magnetic path A1 and the second magnetic path A2 is adjusted by adjusting the area of the cross section substantially orthogonal to the magnetic flux of the cylindrical portion 242. It is good also as composition. [0085] Furthermore, in the second embodiment, the area ratio of the area of the first magnet abutment surface 251 to the area of the second magnet abutment surface 261 is set to the desired magnetic flux density of the first magnetic gap G1 and the second magnetic gap G2. Although it adjusted according to the ratio of the size of, it is not restricted to this. For example, the area ratio of the area of the cross section substantially orthogonal to the magnetic flux of the first barrel 250A of the first upper yoke 250 and the area of the cross section substantially orthogonal to the magnetic flux of the second barrel 260A of the second upper yoke 260 The ratio may be adjusted according to the ratio of the magnetic flux density of the magnetic gap G1 and the second magnetic gap G2, and the area ratio of the area of the first magnet abutment surface 251 and the area of the second magnet abutment surface 261 and Both the area ratio of the area of the cross section substantially orthogonal to the magnetic flux of the first body 250A and the area ratio of the area of the cross section substantially orthogonal to the magnetic flux of the second body 260A may be adjusted. [0086] In the first embodiment, the cross-sectional area S3 substantially orthogonal to the magnetic flux in the magnet contact portion 221 of the first pole 220 is adjusted according to the total amount of magnetic flux flowing through the magnetic body, and the second embodiment is implemented. In the embodiment, the contact area S4 of the bottom 241 of the lower yoke 240 with the magnet 210A is adjusted according to the total amount of magnetic flux flowing through the magnetic material, but, for example, adjusting the cross-sectional area S3 and the contact area S4. Alternatively, the configuration of the speaker in which the magnets 210 and 210A having an appropriate magnetic force are selected according to the amount of magnetic flux flowing through the magnetic body may be used, and the speaker magnetic body may be manufactured. 02-05-2019 33 [0087] In addition, the specific structure and procedure at the time of implementation of this invention can be suitably changed into another structure etc. in the range which can achieve the objective of this invention. [0088] [Effects of the Embodiment] As described above, in the speaker 100, the first magnetic path A1 is formed by the magnet 210, the first pole 220, and the inner annular portion 232 of the second yoke 230. A second magnetic path A2 is formed by the pole 220 and the outer annular portion 233 of the second yoke 230, and the magnet 210 from the bottom 231 of the second yoke 230 among the first magnetic path A1 and the second magnetic path A2. A common magnetic path A3 is formed across the tip of the one pole 220 and the inner annular portion 232 of the second yoke 230. The cross-sectional area S3 of the portion of the first pole 220 substantially orthogonal to the magnetic flux of the magnet contact portion 221 is set according to the desired amount of magnetic flux flowing from the magnet 210 to the common magnetic path A3. The cross-sectional area S1 of a portion of the inner annular portion 232 of the second yoke 230 which is substantially orthogonal to the magnetic flux of the first body portion 232B and the magnetic flux of the second body portion 233B of the outer annular portion 233 of the second yoke 230 are substantially orthogonal. The area ratio of the sectional area S2 of the portion is the total magnetic flux passing through the first magnetic gap G1, the amount of magnetic flux in the first magnetic path A1 branched from the inner annular portion 232 to the bottom 231, and the second magnetic gap G2 It is set according to the desired ratio with the amount of magnetic flux in the second magnetic path A2 that passes from the outer annular portion 233 to the bottom portion 231. Therefore, the amount of magnetic flux flowing through each of the first magnetic path A1 and the second magnetic path A2 is appropriately set, and the ratio of the magnetic flux density between the first magnetic gap G1 and the second magnetic gap G2 is also appropriately set. Therefore, the magnitude of the magnetic flux density in the first magnetic gap G1 and the second magnetic gap G2 can be made appropriate. Therefore, the diaphragm 400 of the speaker 100 can be vibrated more appropriately, and a good sound can be output. [0089] 02-05-2019 34 It is a side sectional view showing typically the outline of the speaker concerning a first embodiment. It is a figure which shows typically the magnetic path in the speaker magnetic circuit part of 1st embodiment. It is a side cross-sectional view which shows typically the outline of the speaker which concerns on 2nd embodiment. It is a figure which shows typically the magnetic path in the speaker magnetic circuit part of 2nd embodiment. It is a side sectional view showing typically the outline of the speaker concerning other embodiments. It is a figure which shows typically the magnetic path in the speaker magnetic circuit part in the speaker of FIG. であ る。 Explanation of sign [0090] 200, 200A, 200D ... Magnetic circuit unit as a speaker magnetic circuit section 210, 210A ... Magnet 210C ... Second magnet 210D ... Third magnet 220 ... First pole as magnetic body and common magnetic body 230 ... First as magnetic body Two yokes 231, 234A, 241 ... bottom portion that constitutes a part of the common magnetic body 232 ... inner annular portion as a first magnetic body 232A, 234D, 252 ... first magnetic gap forming surface 232B, 234C, 250A ... first barrel Portion 233: Outer annular portion 233A, 236C, 262 as second magnetic body: Second magnetic gap forming surface 233B, 236A, 260A: Second body portion 234: Lower yoke as magnetic body 234B: As first magnetic body An annular portion 235 of the first upper yoke as a common magnetic body 235A, 242 as a common magnetic body barrel Column part 236 ... Second upper yoke as a second magnetic body 240 ... Lower yoke as a magnetic body constituting a part of a common magnetic body 243 ... Gap forming surface as a common magnetic body side gap forming surface 250 ... Magnetic body Body and first upper yoke as first magnetic body 251 ... first magnet abutment surface 260 ... second upper yoke as magnetic body and second magnetic body 261 ... second magnet abutment surface 400 ... diaphragm 512 ... coil Outer voice coil as part 522 ... Inner voice coil as coil part A1 ... First magnetic path A2 ... Second magnetic path A3 ... Common magnetic path G1 ... First magnetic gap G2 ... Second magnetic gap 02-05-2019 35
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