JP2009118020A - Magnetic circuit for loudspeaker, manufacturing method thereof and loudspeaker using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To achieve a flat thin loudspeaker capable of obtaining flat frequency characteristic while hardly causing split vibration, and to provide a magnetic circuit for a loudspeaker hardly causing operation failure, having high working efficiency in manufacturing and suppressing a manufacturing cost at low level. <P>SOLUTION: The magnetic circuit module is configured of a plurality of coupled magnetic circuit modules each having a substantially planar plate, a main magnet fixed on the bottom of the plate, and a yoke fixed on the bottom of the main magnet, wherein the yoke of each of the magnetic circuit modules has a sidewall portion forming a substantially linear gap Ga in between at least one side of the substantial rectangular of the plate and a coupling portion used to fix to the yoke of another magnetic circuit module adjacently provided. The plates of the first and second magnetic circuit modules whose coupling portions are coupled communicate with the magnetic gap Ga, and form a substantially linear magnetic gap Gb perpendicular to the magnetic gap Ga. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a speaker magnetic circuit including a plurality of magnets arranged on a plane so that magnetic polarities are different from each other, and a speaker including the magnetic circuit and a speaker vibration member including a plurality of coils. In particular, the present invention relates to a flat thin speaker with a thin overall height.

  In an electrodynamic speaker that converts an audio signal into audio, there is a speaker that employs a flat diaphragm as a speaker diaphragm in order to keep the total height including a magnetic circuit low. Although the overall height of the flat diaphragm is lower than that of the cone diaphragm, the rigidity tends to be insufficient to vibrate integrally without split vibration. Therefore, there is a speaker that has a plurality of voice coils in a bobbin that is fixed to a planar diaphragm, and drives the planar diaphragm with the plurality of voice coils to suppress divided vibration. Conventionally, a speaker including a flat diaphragm having a plurality of coils and a magnetic circuit using a plurality of magnets corresponding to each coil may be used as a flat thin speaker having a thin overall height.

  For example, there is a drive-type speaker that has a thin structure, has a large number of drive points, approaches full-surface drive, and moves a piston from low to high (Patent Document 1). This speaker has a magnetic circuit group in which a plurality of magnetic circuit units each having at least a pair of two parallel magnetic gaps are arranged in a checkerboard shape with the gap directions all parallel to one direction. One flat voice coil is inserted into each magnetic circuit to drive the flat diaphragm.

  In addition, a plurality of angled ridges parallel to each other are arranged side by side, and the diaphragm of the thin film body in which the conductive wires are mounted in series on the valleys of the ridges, and the recesses formed by the alternate ridges should be positioned. Each of the plurality of permanent magnets arranged on the bottom plate has a U-shaped magnetic pole plate in which the tip is intruded into the recesses of the ridges adjacent to the ridge where the permanent magnets are located so as to face the permanent magnets. And a frame body having a bottom plate provided with a plurality of through holes, and a frame body provided with a bulging portion at the central portion connecting the outer peripheral edge of the diaphragm to the peripheral wall. There is an electroacoustic transducer (Patent Document 2).

  On the other hand, a magnet group in which a plurality of permanent magnets each having a square plate top yoke are arranged in parallel on a magnetic plate is arranged so that the magnetic poles of a plurality of magnets are different from each other. In the magnetic base of a planar drive type speaker having a predetermined gap on the outer periphery of the magnet group and having a side yoke, the magnetic plate is formed in a substantially box shape, and the magnetic plate There is a planar drive type speaker characterized in that at least one end is a side yoke (Patent Document 3). Further, in the same full-surface drive type speaker, the width of the permanent magnet located on both outer sides of the magnetic circuit is narrowed to about half of the adjacent permanent magnet, and the voice coil in the diaphragm is formed on the outer wall portion of each vibration element. There is a structure characterized in that it is arranged in a line in the groove formed (Patent Document 4).

JP-A-57-99898 JP 58-207794 A Japanese Utility Model Publication No. 60-150891 Japanese Utility Model Publication No. 61-111292

  However, the magnetic circuit group of Patent Document 1 is merely a plurality of magnetic circuit single elements arranged in a matrix, and each has a single rectangular voice coil inserted into each magnetic circuit single element. In spite of using a large number of magnets, there is a problem that the magnetic efficiency is not good as a whole. The magnetic circuit of Patent Document 2 has a similar configuration. In addition, even if the magnetic circuit of patent document 1 and 2 is a magnetic circuit for speakers containing the several magnet arrange | positioned on a plane, it is arrange | positioned so that the magnetic pole property of several magnets may differ mutually. is not.

  Further, in the magnetic circuit structures of Patent Documents 3 and 4, the widths of the magnetic gaps defined between the top yokes must be precisely defined, but the magnetic poles of the plurality of magnets are different from each other. In order to arrange in such a manner, it is necessary to arrange on a single magnetic plate while suppressing magnets with different magnetic polarities that have been magnetized in advance from attracting or repelling each other, There is a problem that work efficiency in manufacturing is poor.

  The present invention has been made in order to solve the above-described problems of the prior art, and an object thereof is to realize a flat and thin speaker that is less likely to generate divided vibration and obtains a flat frequency characteristic and operates. It is an object of the present invention to manufacture a magnetic circuit for a speaker that is less likely to cause defects, has good manufacturing work efficiency, and has a low manufacturing cost.

  The magnetic circuit for a speaker according to the present invention is a magnetic circuit for a speaker including a plurality of magnets arranged on a plane so that the magnetic polarities are different from each other, and is fixed to a substantially rectangular flat plate and a bottom surface of the plate. A plurality of magnetic circuit modules having a main magnet and a yoke fixed to the bottom surface of the main magnet, and the yoke of the magnetic circuit module is substantially linear between at least one side of a substantially rectangular plate. The first magnetic circuit module and the second magnetic circuit module each having a side wall portion forming the magnetic gap Ga and a connecting portion fixed to a yoke of another adjacent magnetic circuit module. Each plate of the magnetic circuit module forms a substantially linear magnetic gap Gb that communicates with the magnetic gap Ga and is orthogonal to the magnetic gap Ga.

  Preferably, in the magnetic circuit for a speaker according to the present invention, the magnetic circuit module is attached so that the plate side exhibits the one magnetic polarity and the plate side exhibits the other magnetic property. A second magnetic circuit module that is magnetized, and a connecting portion of the yoke that constitutes the first magnetic circuit module includes a fitting convex portion, and a connecting portion of the yoke that constitutes the second magnetic circuit module The fitting convex part of the first magnetic circuit module and the fitting concave part of the second magnetic circuit module are fitted and connected.

  More preferably, the magnetic circuit for a speaker according to the present invention further includes a holding frame that fits the yokes of a plurality of connected magnetic circuit modules, and the yoke of the magnetic circuit module has a fitting holding portion that fits the holding frame. Also have.

  More preferably, in the magnetic circuit for a speaker according to the present invention, each of the magnetic circuit modules further includes a repulsion magnet fixed to the top surface of the plate, and the repulsion magnet forms a repulsion magnetic circuit together with the main magnet.

  Preferably, the speaker of the present invention is a speaker comprising the above-described speaker magnetic circuit, a frame fixed to the speaker magnetic circuit, and a speaker vibration member whose outer peripheral end is fixed to the frame, The speaker vibrating member includes a speaker diaphragm, an edge that supports the outer periphery of the speaker diaphragm so as to vibrate, a bobbin fixed to the back side of the speaker diaphragm, and a plurality of rectangular coils fixed to the bobbin. A plurality of rectangular coils are arranged in the magnetic gaps Ga and Gb.

  The speaker magnetic circuit manufacturing method of the present invention is the speaker magnetic circuit manufacturing method described above, wherein an assembly jig Ja defining the magnetic gap Ga is fitted into the yoke, and the plate, the main magnet, and the yoke Are fixed with an adhesive, and after the adhesive is fixed, the assembly jig Ja is removed to form a plurality of magnetic circuit modules, and the magnetic circuit module is magnetized so as to show one magnetic pole property. A step of forming one magnetic circuit module, a step of forming a second magnetic circuit module by magnetizing another magnetic circuit module so as to exhibit the other magnetic pole property, and an assembly jig for defining the magnetic gap Gb The first magnetic circuit module and the second magnetic circuit module are inserted into Jb, and the connecting portions of the respective yokes are fixedly connected with an adhesive to form the magnetic gap Gb. Including a degree, the steps of overtake the assembly jig Jb after the adhesive has adhered, the.

  Preferably, in the method for manufacturing a magnetic circuit for a speaker according to the present invention, the step of fixing the magnetized repulsive magnet so as to form a repulsive magnetic circuit on the top surface of each plate of the magnetized magnetic circuit module. And a step of fitting the holding frame to the holding fitting portion of the yoke.

  The operation of the present invention will be described below.

  The speaker magnetic circuit of the present invention is configured by connecting a plurality of magnetic circuit modules. One magnetic circuit module has a substantially rectangular flat plate, a main magnet fixed to the bottom surface of the plate, and a yoke fixed to the bottom surface of the main magnet. This yoke has a side wall part that forms a substantially linear magnetic gap Ga between at least one side of the substantially rectangular shape of the plate, and a connecting part that is fixed to the yoke of another magnetic circuit module disposed adjacent to the yoke. ing. Therefore, in the speaker magnetic circuit of the present invention, when the connecting portions of the first magnetic circuit module and the second magnetic circuit module are fixed to each other, the respective plates of the first magnetic circuit module and the second magnetic circuit module It is possible to form a substantially linear magnetic gap Gb that communicates with the magnetic gap Ga and is orthogonal to the magnetic gap Ga.

  The speaker magnetic circuit of the present invention is a speaker magnetic circuit including a plurality of magnets arranged on a plane so that the magnetic polarities are different from each other, and the first and second magnetic circuit modules to be connected are as follows. It is formed through the process. That is, in the plurality of magnetic circuit modules, the assembly jig Ja defining the magnetic gap Ga is fitted into the yoke, the plate, the main magnet, and the yoke are fixed with an adhesive, and the assembly jig Ja is fixed after the adhesive is fixed. It is formed through a process of removing. The first magnetic circuit module is magnetized so as to exhibit one magnetic polarity, and the other second magnetic circuit module connected to the first magnetic circuit module is magnetized so that the plate side exhibits the other magnetic polarity. .

  Therefore, the first and second magnetic circuit modules having different magnetic polarities previously magnetized in different directions may be prepared and connected by the connecting portions of the yokes. A strong magnetic field can be generated also in the magnetic gap Gb, and a speaker magnetic circuit with high magnetic efficiency can be easily configured. In the step of forming the magnetic gap Gb, the first magnetic circuit module and the second magnetic circuit module are fitted into the assembly jig Jb that defines the magnetic gap Gb, and the connecting portions of the respective yokes are connected to each other. Are fixed with an adhesive and connected, and the assembly jig Jb is removed after the adhesive is fixed.

  Preferably, the connecting portion of the yoke constituting the first magnetic circuit module includes a fitting convex portion, and the fitting concave portion in which the connecting portion of the yoke constituting the second magnetic circuit module is fitted to the fitting convex portion. If it is provided, the fitting magnetic convex portion of the first magnetic circuit module and the fitting concave portion of the second magnetic circuit module are fitted and connected to each other, so that the speaker magnetic circuit can be easily configured. It is possible to improve the working efficiency at the time of manufacturing and to suppress the manufacturing cost. The first and second magnetic circuit modules having different magnetization directions are distinguished from each other by yokes having connecting portions having different shapes. Therefore, when assembling the speaker magnetic circuit, the same magnetic pole property is connected next to each other. It is possible to prevent work mistakes.

  In addition, if the yoke of each magnetic circuit module has a fitting holding portion that fits with the holding frame, it can be further strengthened by further including a holding frame that fits the yoke of a plurality of connected magnetic circuit modules. The magnetic circuit modules are connected to each other to realize a speaker magnetic circuit that is less prone to malfunction. Each magnetic circuit module further includes a repulsive magnet fixed to the top surface of the plate, and the repelling magnet has a magnetic polarity different from that of the main magnet on the opposite side of the plate. It may constitute a circuit. A magnetic flux density distribution in the magnetic gaps Ga and Gb is further increased, and a speaker magnetic circuit with high magnetic efficiency is realized.

  The speaker including the speaker magnetic circuit further includes a frame fixed to the speaker magnetic circuit and a speaker vibration member having an outer peripheral end fixed to the frame. The speaker vibration member includes a planar diaphragm as a speaker diaphragm, an edge that supports the outer periphery of the speaker so as to vibrate, a bobbin that is fixed to the back side thereof, and a plurality of rectangular coils that are fixed to the bobbin. ing. The plurality of rectangular coils are disposed in the magnetic gaps Ga and Gb of the speaker magnetic circuit. Accordingly, a flat speaker with a reduced overall height of the speaker is formed, and driving with a plurality of voice coils can suppress divided vibration and achieve a flat frequency characteristic.

  The speaker provided with the magnetic circuit for a speaker of the present invention can realize a flat and thin speaker in which a divided frequency is hardly generated and a flat frequency characteristic can be obtained. The above work efficiency is good and the manufacturing cost can be suppressed.

  The magnetic circuit for a speaker according to the present invention has a purpose of realizing a flat and thin speaker having high efficiency, being difficult to generate divided vibrations, and capable of obtaining a flat frequency characteristic. A magnetic circuit for a speaker comprising a plurality of magnets arranged, the magnetic circuit module having a substantially rectangular flat plate, a main magnet fixed to the bottom surface of the plate, and a yoke fixed to the bottom surface of the main magnet. The yoke of the magnetic circuit module is formed by connecting a side wall portion that forms a substantially linear magnetic gap Ga between at least one side of the substantially rectangular plate, and another magnetic circuit module disposed adjacent to the yoke. Each of a first magnetic circuit module and a second magnetic circuit module each having a connecting portion fixed to the yoke, wherein the connecting portions are fixed to each other Plates to each other, communicating with the magnetic gap Ga, and, by so as to form a substantially linear magnetic gap Gb perpendicular to the magnetic gap Ga, was realized.

  Hereinafter, a magnetic circuit for a speaker according to a preferred embodiment of the present invention, a manufacturing method thereof, and a speaker using the magnetic circuit will be described, but the present invention is not limited to these embodiments.

  FIG. 1 is a diagram illustrating a speaker magnetic circuit according to a preferred embodiment of the present invention. FIG. 1A is a perspective view for explaining a magnetic circuit module 10 constituting the magnetic circuit 2, and FIG. 1B is a perspective view for explaining the magnetic circuit 2. The magnetic circuit 2 of this embodiment is configured by connecting six magnetic circuit modules 10. That is, the magnetic circuit 2 includes three magnetic circuit modules 10a and a magnetic circuit in which the magnetization direction is reversed with respect to the magnetic circuit module 10a so that the magnetic poles of the magnets of the magnetic circuit module 10 are different from each other. The modules 10b are connected so as to appear alternately in a line.

  Each magnetic circuit module 10 includes a substantially rectangular flat plate 11, a main magnet 12 fixed to the bottom surface of the plate 11, a yoke 13 fixed to the bottom surface of the main magnet 12, and a repulsive magnet fixed to the top surface of the plate 11. 14 and. The plate 11 and the yoke 13 are made of a magnetic material such as soft iron or permalloy. The main magnet 12 and the repulsive magnet 14 are made of a magnet material containing a rare earth such as neodymium. The plate 11, the main magnet 12, the yoke 13, and the repulsion magnet 14 are fixed with an adhesive. Further, the yoke 13 is provided with a side wall portion 13a that forms a substantially linear magnetic gap Ga between one side of a substantially rectangular shape of the plate 11, and in the case of the present embodiment, two parallel side wall portions 13a. Corresponding to, the magnetic gap Ga is formed on two substantially rectangular sides. Since the main magnet 12 and the repulsive magnet 14 are arranged so that the surfaces of the magnets having the same magnetic polarity sandwich the plate 11, a repulsive magnetic field having a high magnetic flux density is formed in the magnetic gap Ga.

  Further, the yoke 13 of the magnetic circuit module 10 has a substantially concave cross-sectional shape, and both end faces showing the substantially concave shape are connected to the yokes of other magnetic circuit modules arranged adjacent to each other. Part 13b is formed. That is, the connecting portion 13b is a portion where the yoke 13 of the magnetic circuit module 10 is in close contact with the yoke 13 of the other magnetic circuit module 10, functions as a portion through which the magnetic lines of force of the magnetic circuit 2 pass, and is bonded. The magnetic circuit modules are mechanically connected to each other by being fixed with an agent.

  Further, the connecting portions 13b of the magnetic circuit module 10 are fixed to each other, so that the plates 11 of the magnetic circuit modules 10a and 10b communicate with the magnetic gap Ga and are substantially linearly orthogonal to the magnetic gap Ga. The magnetic gap Gb is formed. Since the magnetization directions of the magnetic circuit modules 10a and 10b are opposite to each other, a magnetic field showing a high magnetic flux density is also formed in the magnetic gap Gb defined between them. Since the six magnetic circuit modules 10 are connected in a line, the magnetic gap Ga of the magnetic circuit module 10a and the magnetic gap Ga of the magnetic circuit module 10b are arranged in a straight line, so that the magnetic circuit 2 As a whole, a lattice-like (or ladder-like) magnetic gap composed of the magnetic gap Ga and the magnetic gap Gb is formed.

  FIG. 2 is a diagram for explaining a method of manufacturing the speaker magnetic circuit according to this embodiment. FIG. 2A is a perspective view illustrating a manufacturing process of the magnetic circuit module 10, and FIG. 2B is a perspective view illustrating a manufacturing process of the magnetic circuit 2. Each of the plurality of magnetic circuit modules 10 is manufactured using an assembly jig Ja that defines the magnetic gap Ga, and the magnetic circuit 2 constituted by these magnetic circuit modules 10 uses the assembly jig Jb. Manufactured.

  As shown in FIG. 2A, the assembly jig Ja is inserted between the plate 11 and the side wall 13a of the yoke 13 to define the magnetic gap Ga. The assembly jig Ja is a cylindrical body having a substantially rectangular cross-sectional shape that covers the periphery of the plate 11, and includes a space for accommodating the plate 11 and the main magnet 12 therein. Further, since the assembly jig Ja has a protruding portion that engages with the connecting portion 13b of the yoke 13, the assembly jig Ja is applied after applying an adhesive to the plate 11 and the non-magnetized main magnet 12. Is inserted into the yoke 13, the relative positional relationship between the plate 11 and the yoke 13 defining the magnetic gap Ga and the magnetic gap Gb is uniquely fixed. Therefore, when the assembly jig Ja is removed after the adhesive is fixed, the magnetic circuit module 10 having the magnetic gap Ga and not magnetized is formed.

  Next, this non-magnetized magnetic circuit module 10 is magnetized to form a magnetic circuit module 10a showing one magnetic pole property and a magnetic circuit module 10b showing the other magnetic pole property on the plate 11 side, respectively. To do. As described above, the magnetic circuit modules 10a and 10b are merely reversed in the magnetization direction in the magnetization process, and can be easily distinguished by applying some marking. Then, the repulsion magnet 14 magnetized in advance is fixed to the top surface of the plate 11 of each of the magnetic circuit modules 10a and 10b. As described above, the repelling magnets 14 are fixed after their orientations are confirmed so as to form a repulsive magnetic field.

  As shown in FIG. 2B, the magnetic circuit 2 is manufactured by connecting the magnetic circuit modules 10a and 10b using an assembly jig Jb. The assembling jig Jb is a lattice-shaped jig having such a dimension that the connecting portions 13b of the yokes 13 of the six magnetic circuit modules 10a and 10b inserted into close contact with each other. The grid-like wall portions that separate from each other define the magnetic gap Gb formed by the plates 11. When the magnetic circuit modules 10a and 10b that have been previously magnetized in different directions and have different magnetic polarities are inserted into the assembly jig Jb so that different magnetic polarities appear alternately, an adhesive is applied to the connecting portion 13b. If the connecting parts 13b of the yokes 13 having different magnetic polarities are fixed to each other and the assembly jig Jb is removed after the adhesive is fixed, the magnetic circuit 2 is formed.

  Note that the magnetic circuit 2 shown in FIG. 2B further includes holding frames 3 that fit into the respective yokes 13. The holding frame 3 is a member having a substantially concave cross section formed so as to cover all the magnetic circuit modules 10 from the back side of the magnetic circuit 2, and is fixed to the yoke 13 with an adhesive. The holding frame 3 may be a magnetic material such as iron as illustrated, or a nonmagnetic material such as aluminum or resin. Since the holding frame 3 is fitted to all the yokes 13, the magnetic circuit modules 10a and 10b are reinforced by reinforcing the adhesion and fixing of the connecting portions 13b, and the magnetic circuit for a speaker is less likely to cause malfunction. 2 can be realized. The assembly jig Jb may be removed before the holding frame 3 is fixed, but preferably after the holding frame 3 is fixed as shown in FIG.

  The speaker magnetic circuit 2 of the present invention composed of a plurality of magnetic circuit modules 10 can form a repulsive magnetic field having a high magnetic flux density in both the magnetic gap Ga and the magnetic gap Gb. In the conventional magnetic circuit, the connecting portions 13b of the yoke 13 are closely adhered and fixed by using the assembly jig Jb, compared to the case where the yoke is composed of one member that is not divided. As long as it is present, the magnetic flux density is not significantly reduced by the magnetic gaps Ga and Gb.

  On the other hand, the process of preparing magnetic circuit modules 10a and 10b having different magnetization directions in advance is basically the same as the process of magnetizing a magnetic circuit used for a normal speaker. There is an advantage that it can be used as it is. That is, even if it is the magnetic circuit 2 for speakers provided with a some magnet, the working efficiency in manufacture is good and manufacturing cost can be suppressed. Also, by preparing the magnetic circuit modules 10a and 10b as repulsive magnetic circuits, it is not necessary to handle only a small magnetized main magnet when assembling the speaker magnetic circuit 2, so that the work efficiency is increased. improves.

  For example, when a larger magnetic circuit is required, the number of magnetic circuit modules constituting the magnetic circuit is further increased to 8, 10, and an assembly jig corresponding to the number of magnetic circuit modules. It is sufficient to prepare Jb, and it is possible to cope with various design change requests. Therefore, the speaker magnetic circuit 2 with high magnetic efficiency can be easily configured.

  FIG. 3 is a diagram for explaining a magnetic circuit module constituting a speaker magnetic circuit according to another preferred embodiment of the present invention. 3 (a), 3 (b) and 3 (c) are plan views for explaining the magnetic circuit modules 10a and 10b constituting the magnetic circuit 2, and the shape of the connecting portion 13b of the yoke 13 is fitted. This is different from the previous embodiment in that it has a fitting uneven portion. In addition, the same code | symbol is attached | subjected to the same part as a previous Example, and description is abbreviate | omitted. In FIG. 3, the repulsion magnet 14 is not shown, but the magnetic circuit module exhibits a high magnetic flux density in both the magnetic gap Ga and the magnetic gap Gb even if the repulsion magnet 14 is not provided. What is necessary is just to have the main magnet 12 which forms a magnetic field.

  For example, the magnetic circuit modules 10a and 10b shown on the left side of the arrow in FIG. The connecting portion 13b of the yoke 13 of the magnetic circuit module 10a includes a fitting convex portion 13ba in which the central portion of the connecting portion 13b protrudes, while the connecting portion 13b of the yoke 13 of the adjacent magnetic circuit module 10b is connected to the connecting portion 13b. A fitting recess 13bb that is recessed so that the central portion of 13b corresponds is provided. That is, the shape of the yoke 13 is different between the magnetic circuit modules 10a and 10b. Then, as shown on the right side of the arrow in FIG. 3A, the fitting convex portion 13ba of the magnetic circuit module 10a and the fitting concave portion 13bb of the magnetic circuit module 10b are fitted and connected, and the magnetic circuit 2 Is configured.

  As described above, on the plate 11 side, the magnetic circuit module 10a showing one magnetic polarity and the magnetic circuit module 10b showing the other magnetic polarity are respectively magnetized in opposite directions. The magnetic circuit modules 10a and 10b must be fitted into the assembly jig Jb so that different magnetic polarities appear alternately. However, since the shape of the yoke 13 is different between the magnetic circuit modules 10a and 10b, It is possible to eliminate erroneously connecting magnetic circuit modules having the same magnetic pole property between adjacent ones. That is, if the fitting convex portion 13ba and the fitting concave portion 13 are provided in the connecting portion 13b of the yoke 13, the magnetic circuit modules having different magnetization directions cannot be arranged without a gap unless they are adjacent to each other. Since it does not fit, the magnetic circuit 2 can be assembled without making a mistake and work efficiency can be improved.

  Further, in the magnetic circuit modules 10a and 10b shown on the left side of the arrow in FIG. 3B, as in the case of FIG. 3A, the connecting portion 13b of the yoke 13 of the magnetic circuit module 10a is one side of the connecting portion 13b. On the other hand, the connecting part 13b of the yoke 13 of the adjacent magnetic circuit module 10b is recessed so that a part of more than half of one side of the connecting part 13b corresponds. A mating recess 13bb is provided. That is, the magnetic circuit modules 10a and 10b are different in the shape of the yoke 13, and the shapes of the fitting convex part and the fitting concave part are modifications in the case of FIG. Then, as shown on the right side of the arrow in FIG. 3B, the fitting convex portion 13ba of the magnetic circuit module 10a and the fitting concave portion 13bb of the magnetic circuit module 10b are fitted and connected, and the magnetic circuit 2 Is configured.

  However, the yoke 13 of the magnetic circuit module 10 a includes fitting protrusions 13 ba at the connecting portions 13 b at both ends, and these two fitting protrusions 13 ba are point-symmetric with respect to the center point O of the yoke 13. It has become a relationship. Further, the yoke 13 of the magnetic circuit module 10b also includes fitting recesses 13bb at the connecting portions 13b at both ends, and these two fitting recesses 13bb are point-symmetric with respect to the center point O of the yoke 13. It has become. Therefore, as shown in FIG. 3B, not only can the magnetic circuit module 10b be connected to the right side of the magnetic circuit module 10a, but also the magnetic circuit module 10b can be connected to the left side of the magnetic circuit module 10a. .

  Further, in the magnetic circuit modules 10a and 10b shown on the left side of the arrow in FIG. 3C, as in the case of FIG. 3A, the connecting portion 13b of the yoke 13 of the magnetic circuit module 10a protrudes at the center. On the other hand, the connecting portion 13b of the yoke 13 of the adjacent magnetic circuit module 10b is provided with a fitting recess 13bb that is depressed so that the central portion of the connecting portion 13b corresponds. The fitting convex portion 13ba and the fitting concave portion 13bb each have sides where the concave and convex portions are fitted at an angle of about 45 °. Further, in these magnetic circuit modules 10a and 10b, as in the case of FIG. 3B, each yoke 13 is provided with a fitting convex portion 13ba and a fitting concave portion 13bb on the connecting portion 13b at both ends. . Therefore, as shown in FIG. 3C, not only can the magnetic circuit module 10b be connected to the right side of the magnetic circuit module 10a, but also the magnetic circuit module 10b can be connected to the left side of the magnetic circuit module 10a. .

  In addition, in the connection part of the yoke which comprises a magnetic circuit module, the shape of a fitting convex part and a fitting recessed part, and its combination are not restricted to said Example. The magnetic circuit modules 10a and 10b that are magnetized so that different magnetic polarities appear are different in shape of the yoke 13 so that they can be easily distinguished, and the connecting portions 13b can be fitted together. If it exists, it may be another shape (not shown) such as an arc-shaped cross section.

  Although not shown, when the yoke 13 of the magnetic circuit module 10 includes only one side wall portion 13a corresponding to one side of the rectangle, the yoke 13 is provided with the connecting portion 13b on the other three sides of the rectangle. If the shape is changed, a speaker magnetic circuit including a plurality of magnets arranged in a matrix of two rows and two or more columns can be manufactured by the manufacturing method of the present invention. Also, a speaker magnetic circuit including a plurality of magnets arranged in a matrix of 3 rows and 3 columns can be manufactured by the manufacturing method of the present invention. The yoke 13 of the magnetic circuit module 10 located on the outermost peripheral side of the magnetic circuit 2 is provided with only one side wall portion 13a corresponding to one side of the rectangle, and the magnetic circuit module 10 located inside the magnetic circuit 2 The yoke 13 need only be a bottom surface portion that does not have one side wall portion.

  FIG. 4 is a diagram illustrating a flat and thin speaker 1 using the speaker magnetic circuit 2 according to a preferred embodiment of the present invention. 4A is a perspective view for explaining the speaker 1 with the planar diaphragm 6 facing upward, and FIG. 4B is a cross-sectional view of the speaker 1 taken along the line A-A ′. The speaker magnetic circuit 2 is a magnetic circuit formed by connecting the 14 magnetic circuit modules 10 described in the first embodiment in a row, and a holding frame that fits into the yoke of each magnetic circuit module 10. 3 is provided. Therefore, the description and illustration of the overlapping parts and some internal structures unnecessary for the description are omitted.

  The speaker 1 is a flat and thin speaker including a speaker vibration member 5 including a substantially rectangular flat diaphragm 6, and the planar diaphragm is longer than a length L (about 140.8 mm) that forms the diaphragm area. 6 is a speaker in which a width W (about 16.2 mm) of 6 and an overall height h (about 20.0 mm) as a speaker are suppressed to be small. Specifically, a speaker magnetic circuit 2 and a resin frame 4 that is fixed to the magnetic circuit 2 and supports the periphery of the speaker vibration member 5 are further provided.

  The speaker vibrating member 5 includes a flat diaphragm 6, an edge 7 that supports the outer periphery of the flat diaphragm 6 so as to vibrate, a bobbin 8 that is fixed to the back side of the flat diaphragm 6, and a set of rectangular bobbins 8. A plurality of rectangular coils 9 fixed to the body. Specifically, the planar diaphragm 6 is a molded plate of foamed resin (material: PSP (polystyrene paper)), and its outer peripheral portion is supported by a roll-shaped edge 7 containing rubber (material: foamed rubber). ing. The bobbin 8 is a bobbin in which the rectangular coil 9 is dropped into a lattice-shaped gap formed by forming a film, and the rectangular coil 9 is wound around the rectangular bobbin. Are arranged in the magnetic gaps Ga and Gb of the magnetic circuit 2 for speakers. Therefore, when an audio signal current is supplied to the rectangular coil 9, the bobbin 8 receives a driving force by the magnetic circuit 2, and as a result, when the flat diaphragm 6 vibrates, the flat thin speaker 1 reproduces sound.

  In the magnetic gap Gb of the speaker magnetic circuit 2, the magnetic field lines fly from the N pole to the S pole where the magnetic poles are different from each other, so that the magnetic pole property on the plate 11 side of the magnetic circuit module 10 a is assumed to be N If it is a pole, the magnetic pole property on the plate 11 side of the adjacent magnetic circuit module 10b is the S pole. Accordingly, in each of the magnetic gaps Ga and Gb provided in the magnetic circuit 2, the lines of magnetic force jump in the direction according to the arrangement of the main magnet 12 and the repulsive magnet 14, and a high magnetic flux density distribution is obtained.

  Fourteen rectangular coils 9 are arranged by bobbins 8 in the respective magnetic gaps Ga and Gb of the magnetic circuit 2. The bobbin 8 arrange | positions the 14 rectangular coils 9 about each of the 14 plates 11 so that the magnetic space | gap formed in the circumference | surroundings may be wound. At this time, the adjacent coils 9 are connected so that the audio signal current flowing through each coil is in a reverse rotation direction. For example, when a positive current flows in the coil 9 (not shown) arranged in the magnetic gaps Ga and Gb of the magnetic circuit module 10a in the clockwise direction when viewed from above, the magnetic gap of the adjacent magnetic circuit module 10b Similarly, the coils 9 (not shown) arranged in Ga and Gb are connected to each other so that a positive current flows counterclockwise as viewed from above.

  In this case, an electromagnetic force acts on all the coils 9 in either one of the upper surface direction and the lower surface direction, so that a driving force acts on the bobbins 8 in which these coils 9 are arranged in the magnetic gaps Ga and Gb. The plate 6 is displaced upward or downward. Thus, the 14 coils 9 are connected to each other so that the directions of the driving forces acting on the bobbin 8 coincide. Therefore, the flat and thin speaker 1 of the present embodiment uses the magnetic circuit 2 for the speaker, so that the work efficiency in manufacturing can be improved and the manufacturing cost can be suppressed at a low cost, but the divided vibration hardly occurs. Stable operation is possible with high input resistance.

  In connecting the plurality of coils 9 to each other, it does not matter whether they are connected in series or in parallel. In consideration of the impedance of each coil and the combined impedance of the whole, the connection may be made using both serial connection and parallel connection. Moreover, in order to make the rotation direction in which the audio signal current flows the adjacent coils be in the reverse rotation direction, two types of coils in which the winding directions of the plurality of coils 9 are changed may be prepared, Even if the winding directions of all the coils 9 are the same, the winding start side and the winding end side may be switched and connected to each other. The 14 coils 9 are supplied with an audio signal current via a terminal (not shown) and a tinsel wire (not shown) connected thereto.

  Further, the flat thin speaker 1 of the present embodiment is a case where all the 14 main magnets 12 and the coils 9 are common and square, but the number of magnets and coils may be two or more. Moreover, if it is a rectangle, a rectangle may be sufficient. The bobbin 8 may be an assembly of bobbins in which a plurality of rectangular bobbins are fixed close to each other.

  In addition, about the manufacturing method of the magnetic circuit 2 for speakers of a present Example, as long as each process of said manufacturing method is included, other processes may be further included in order to improve the working efficiency. However, the present invention is not limited to the above description.

  The speaker vibration member and the manufacturing method thereof according to the present invention can be applied not only to a speaker having a planar diaphragm but also to a headphone diaphragm.

It is a figure explaining the magnetic circuit for speakers by preferable embodiment of the present invention. Example 1 It is a figure explaining the manufacturing method of the magnetic circuit for speakers of a present Example. Example 1 It is a figure explaining the magnetic circuit module which comprises the magnetic circuit for speakers by other preferable embodiment of this invention. (Example 2) It is a figure explaining the flat thin speaker by preferable embodiment of this invention. (Example 3)

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Speaker 2 Magnetic circuit 3 Holding frame 4 Frame 5 Speaker vibration member 6 Planar diaphragm 7 Edge 8 Bobbin 9 Coil 10, 10a, 10b Magnetic circuit module 11 Plate 12 Main magnet 13 Yoke 13a Side wall part 13b Connection part 14 Repulsive magnet Ga, Gb Magnetic gap Ja, Jb Assembly jig

Claims (7)

A speaker magnetic circuit comprising a plurality of magnets arranged on a plane so that the magnetic poles are different from each other,
A plurality of magnetic circuit modules each having a substantially rectangular flat plate, a main magnet fixed to the bottom surface of the plate, and a yoke fixed to the bottom surface of the main magnet are connected to each other.
The yoke of the magnetic circuit module is fixedly connected to a side wall portion that forms a substantially linear magnetic gap Ga between at least one side of the substantially rectangular shape of the plate, and a yoke of another magnetic circuit module disposed adjacent thereto. And
The plates of the first magnetic circuit module and the second magnetic circuit module to which the connecting portions are fixed are communicated with the magnetic gap Ga and are substantially straight lines perpendicular to the magnetic gap Ga. A magnetic gap Gb is formed
Magnetic circuit for speakers. The magnetic circuit module is magnetized so that the plate side exhibits one magnetic polarity and the second magnetic circuit magnetized so that the plate side exhibits the other magnetic polarity A circuit module,
The connecting portion of the yoke constituting the first magnetic circuit module includes a fitting convex portion, and the connecting portion of the yoke constituting the second magnetic circuit module is fitted to the fitting convex portion. With a mating recess
The fitting convex part of the first magnetic circuit module and the fitting concave part of the second magnetic circuit module are fitted and connected;
The magnetic circuit for a speaker according to claim 1. A holding frame that fits into the yokes of the plurality of magnetic circuit modules connected to each other; and the yoke of the magnetic circuit module further includes a fitting holding portion that fits into the holding frame;
The speaker magnetic circuit according to claim 1 or 2. Each of the magnetic circuit modules further comprises a repulsive magnet fixed to the top surface of the plate, and the repelling magnet constitutes a repulsive magnetic circuit together with the main magnet.
The magnetic circuit for a speaker according to any one of claims 1 to 3. A speaker comprising: the speaker magnetic circuit according to any one of claims 1 to 4, a frame fixed to the speaker magnetic circuit, and a speaker vibration member having an outer peripheral end fixed to the frame.
The speaker vibrating member includes a speaker diaphragm, an edge that supports the outer periphery of the speaker diaphragm so as to vibrate, a bobbin that is fixed to the back side of the speaker diaphragm, and a plurality of rectangles that are fixed to the bobbin. A coil, and
The plurality of rectangular coils are disposed in the magnetic gaps Ga and Gb.
speaker. It is a manufacturing method of the magnetic circuit for speakers according to any one of claims 1 to 4,
An assembly jig Ja defining the magnetic gap Ga is inserted into the yoke, and the plate, the main magnet, and the yoke are fixed with an adhesive. After the adhesive is fixed, the assembly jig Ja is removed. Leaving and forming a plurality of said magnetic circuit modules;
Magnetizing the magnetic circuit module so as to exhibit one magnetic polarity, and forming the first magnetic circuit module; and magnetizing the other magnetic circuit module so as to exhibit the other magnetic polarity. Forming a second magnetic circuit module;
The first magnetic circuit module and the second magnetic circuit module are inserted into an assembly jig Jb that defines the magnetic gap Gb, and the connecting portions of the yokes are fixed with an adhesive. A step of forming the magnetic gap Gb, a step of removing the assembly jig Jb after the adhesive is fixed,
A method for manufacturing a magnetic circuit for a speaker, comprising: Fixing a magnetized repulsive magnet so as to form a repulsive magnetic circuit on the top surface of each of the magnetized magnetic circuit modules; and
Fitting the holding frame to the holding fitting portion of the yoke;
The method for manufacturing a speaker magnetic circuit according to claim 6, further comprising:

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