JP2007306214A - Speaker magnetic circuit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technology concerning a speaker magnetic circuit in which flux density in a magnetic gap can be enhanced while reducing the weight of the speaker magnetic circuit. <P>SOLUTION: The speaker magnetic circuit comprises an annular magnet 12, an annular magnet 13 arranged around the annular magnet 12, an annular magnet 12a arranged below the annular magnet 12, an annular magnet 13a arranged below the annular magnet 13, a tubular magnetic body 31 having an upper portion connected to the circumferential wall face inside the annular magnet 12 and a lower portion connected to the circumferential wall face inside the annular magnet 12a, a tubular magnetic body 32 having an upper portion connected to the circumferential wall face outside the annular magnet 13 and a lower portion connected to the circumferential wall face outside the annular magnet 13a, and a hollow section formed in the tubular magnetic body 31. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a speaker magnetic circuit.

  FIG. 1 is a sectional view of a magnetic circuit 50 of a conventional general speaker. A magnetic circuit 50 of a conventional general speaker shown in FIG. 1 is a circuit called an internal magnet type in which a voice coil 2 is wound around a disk-shaped magnet 10. The magnetic flux emitted from the N pole of the magnet 10 passes through the yoke 1, the magnetic gap g, and the plate 8 in this order, and reaches the S pole of the magnet 10. When a current is passed through the voice coil 2 arranged in the magnetic field of the magnetic gap g, a force is generated in a direction perpendicular to the magnetic field lines, that is, in the vertical direction on the paper surface, and the voice coil 2 vibrates in the vertical direction on the paper surface. This vibration is transmitted to the cone type diaphragm 5 via the voice coil bobbin 9. As a result, the cone type diaphragm 5 generates sound waves. The center cap 6 is attached to the cone-type diaphragm, and prevents the cone-type diaphragm from being deformed in the radial direction and the entry of dust and the like. The damper 4 holds the voice coil 2 so as to be within a predetermined magnetic field and suppresses the voice coil 2 from vibrating indefinitely. The frame 7 holds the cone type diaphragm 5.

Moreover, the technique of patent document 1-patent document 6 is known as a speaker magnetic circuit and the speaker apparatus using a speaker magnetic circuit. For example, in the technique described in Patent Document 1, an annular magnetic body made of a material having a higher saturation magnetic flux density than the yoke is disposed on the inner bottom surface of the yoke existing around the rising portion of the pole piece portion. As a result, most of the magnetic flux passes through the magnetic body disposed on the inner bottom surface of the yoke, so that an increase in leakage magnetic flux can be suppressed. As a result, it is easy to increase the magnetic flux of the magnetic gap.
JP 2003-61190 A JP 2001-186588 A JP 2002-58093 A Japanese Patent No. 3360211 Utility Model Registration No. 2577561 JP 2005-151254 A

  In the conventional speaker magnetic circuit, the metallic yoke is in surface contact with the bottom surface of the disk-shaped magnet, and it is necessary to enlarge the yoke in the height direction in order to increase the magnetic gap. A large proportion is composed. In addition, since the conventional speaker magnetic circuit has a metal plate on the upper surface of the magnet, the weight of the magnetic circuit is heavy, and a reduction in weight has been desired. However, if the thickness of the yoke is reduced for weight reduction, the magnetic flux easily leaks to the outside of the yoke, and the magnetic flux cannot sufficiently pass through the yoke, so that the magnetic flux density in the magnetic gap decreases and the sound quality deteriorates. This causes the problem. For this reason, the yoke needs to have a certain thickness, and the conventional technology relating to the speaker magnetic circuit cannot achieve a sufficient weight reduction.

  In view of the above problems, an object of the present invention is to provide a technique related to a speaker magnetic circuit capable of reducing the weight of the speaker magnetic circuit and improving the magnetic flux density in the magnetic gap.

In the present invention, the following means are adopted to solve the above-described problems. That is, an annular first magnet magnetized in the radial direction and a magnetic gap into which a voice coil for transmitting vibration to the speaker diaphragm is inserted around the outer peripheral wall surface of the first magnet. A first magnetic flux generator having a ring-shaped and radially magnetized second magnet, and a magnet disposed below the first magnetic flux generator. A second magnetic flux generation unit having contact with at least the inner peripheral wall surface of the first magnet, the outer peripheral wall surface of the second magnet, and the magnet of the second magnetic flux generation unit. And a magnetic body portion that transmits magnetic flux between the magnetic flux generating portion and the second magnetic flux generating portion.

  The speaker magnetic circuit according to the present invention has a configuration in which a voice coil is inserted into a magnetic gap formed between an annular first magnet and an annular second magnet having a larger diameter. By using an annular magnet, a hollow portion can be formed near the center of the speaker. As a result, the weight of the speaker magnetic circuit can be reduced. Moreover, the speaker magnetic circuit according to the present invention includes another magnetic flux generation unit in addition to the first magnetic flux generation unit including the first magnet and the second magnet. And the magnetic flux which generate | occur | produced from the 2nd magnetic flux generation part is transmitted by the magnetic body part. Thereby, the magnetic flux density of a magnetic gap can be improved.

  The first magnetic flux generator has an annular first magnet and an annular second magnet having different diameters. A gap is formed between the outer peripheral wall surface of the first magnet and the inner peripheral wall surface of the second magnet. The first magnet and the second magnet are magnetized in the radial direction. Magnetization is performed so that the directions of magnetic fluxes generated from the first magnet and the second magnet coincide. As a result, a magnetic flux flows toward one of the side surfaces in the gap. That is, this gap functions as a magnetic gap of the speaker magnetic circuit. The voice coil vibrates by inserting a voice coil into the magnetic gap and passing a current. The vibration of the voice coil is transmitted to the diaphragm of the speaker, and the speaker can emit sound. The central axes of the first magnet and the second magnet are preferably arranged on the same axis. By making the first magnet and the second magnet into an annular shape and arranging these two magnets coaxially, the stability of the magnetic flux in the magnetic gap can be improved.

  The second magnetic flux generation unit is disposed below the first magnetic flux generation unit. And the 2nd magnetic flux generation part has a magnet. By efficiently transmitting the magnetic flux generated from the second magnetic flux generation section into the magnetic gap, the magnetic flux density in the magnetic gap can be improved as compared with the case where the speaker magnetic circuit is composed of only the first magnetic flux generation section. Can do. The shape and arrangement of the magnets constituting the second magnetic flux generation unit are preferably designed in consideration of the direction of the magnetic flux in the magnetic gap. The magnet of the second magnetic flux generator can be, for example, an annular magnet.

  The magnetic body part transmits magnetic flux between the first magnetic flux generation part and the second magnetic flux generation part. That is, the magnetic body part connects the first magnetic flux generation part and the second magnetic flux generation part. The magnetic body portion is formed so as to be in contact with at least the inner peripheral wall surface of the first magnet, the outer peripheral wall surface of the second magnet, and the magnet of the second magnetic flux generation unit. Thereby, one closed circuit can be formed. Note that the connection between the first magnetic flux generator and the second magnetic flux generator is preferably performed in consideration of preventing leakage of the magnetic flux. Therefore, for example, when each of the first magnet and the second magnet constituting the first magnetic flux generation unit and the magnet constituting the second magnetic flux generation unit are annular, the magnetic body portion is cylindrical. It is preferable that Thereby, the surrounding wall surface of a cyclic | annular magnet and the surrounding wall surface of a magnetic body part can be stuck, and can be connected. As a result, leakage of magnetic flux can be prevented. In addition, a magnetic body part can be made from iron oxide, chromium iron oxide, cobalt, ferrite, or the like. A magnet can be used as the magnetic body portion, but in this case, it is preferable to arrange carefully so as not to disturb the flow of magnetic flux.

Further, the present invention is a magnet having a first annular portion and a first cylindrical portion connected to the inner lower surface of the first annular portion, wherein the first annular portion is attached in the radial direction. An eighth magnet that is magnetized and magnetized in a direction that is axial and does not oppose the magnetic flux generated by the first annular portion; and an outer periphery of the first annular portion. A second annular portion arranged to form a magnetic gap into which a voice coil for transmitting vibration to the speaker diaphragm is inserted around the wall surface, and connected to an outer lower surface of the second annular portion A magnet having a second cylindrical portion, wherein the second annular portion is magnetized in a radial direction, and the second cylindrical portion has an axis opposite to a magnetic flux generated from the first cylindrical portion. A ninth magnet that is magnetized in a direction that does not oppose the magnetic flux generated from the second annular portion, and the first cylindrical portion A third cylindrical portion having substantially the same diameter, a fourth cylindrical portion having substantially the same diameter as the second cylindrical portion, a lower portion of the third cylindrical portion, and a lower portion of the fourth cylindrical portion are connected. A magnet having a donut disk portion, wherein the third cylindrical portion is magnetized in a direction coaxial with a direction of magnetic flux generated from the first cylindrical portion, and the fourth cylindrical portion is the second cylindrical portion. The doughnut disk is magnetized in the radial direction so as to be opposite to the direction of the magnetic flux generated from the first annular portion. A magnetic circuit of the speaker.

  In the present invention, the speaker magnetic circuit is entirely composed of magnets. The speaker magnetic circuit according to the present invention includes a first magnet, a second magnet, and a third magnet. With this configuration, the speaker magnetic circuit can be reduced in weight and the magnetic flux density in the magnetic gap can be improved. The first magnet, the second magnet, and the third magnet are preferably bonded magnets. Thereby, a magnet can be easily molded.

  ADVANTAGE OF THE INVENTION According to this invention, the technique regarding the speaker magnetic circuit which can aim at weight reduction of a speaker magnetic circuit and can improve the magnetic flux density in a magnetic gap can be provided.

  Next, an embodiment of a speaker magnetic circuit according to the present invention will be described with reference to the drawings.

  FIG. 2 is a cross-sectional view of the speaker magnetic circuit 52 according to the first embodiment. FIG. 3 is a top view of the speaker magnetic circuit 52 according to the first embodiment. The speaker magnetic circuit 52 according to the first embodiment includes an annular magnet 12, an annular magnet 13 disposed around the annular magnet 12, and an annular magnet 12 a disposed below the annular magnet 12. An annular magnet 13a disposed below the annular magnet 13 and a cylindrical magnetic body having an upper portion connected to the inner peripheral wall surface of the annular magnet 12 and a lower portion connected to the inner peripheral wall surface of the annular magnet 12a. 31, a cylindrical magnetic body 32 whose upper part is connected to the outer peripheral wall surface of the annular magnet 13 and whose lower part is connected to the outer peripheral wall surface of the annular magnet 13a, and a cylindrical magnetic body 31 formed inside. The hollow part 20 is provided. The annular magnet 12a and the annular magnet 13a are fixed to the upper surface of the circular plate A. The circular plate A can be formed of a resin or a magnetic material, and these can be used by selecting a material according to the purpose. For example, when a magnetic material is used, leakage of magnetic flux in the magnetic circuit can be prevented. Moreover, when using resin, the speaker can be reduced in weight. The annular magnets 12 and 13 correspond to the first magnetic flux generator of the present invention. The annular magnets 12a and 13a correspond to the second magnetic flux generator of the present invention. The cylindrical magnetic bodies 31 and 32 correspond to the magnetic body portion of the present invention.

  The annular magnet and the magnetic body can be connected by an adhesive. As the magnet, an alnico magnet, a ferrite magnet, a neodymium magnet, or the like can be used. Preferably, a rare earth magnet that can increase the magnetic flux density or a rare earth bonded magnet that is excellent in size reduction and weight reduction can be used. Furthermore, it is more preferable to use an anisotropic rare earth bonded magnet that has excellent magnetic properties, can be easily formed into a thin ring shape, and has a density smaller than that of a sintered magnet. The magnetic material can be exemplified by iron oxide and the resin can be exemplified by polypropylene and the like.

The annular magnets 12, 12a, 13, 13a according to the first embodiment all have the same radial width and height. That is, the annular magnet 12 and the annular magnet 12a have the same shape and differ only in the magnetization direction. Also, the annular magnet 13 and the annular magnet 13a have the same shape and differ only in the magnetization direction. That is, it is possible to form the annular magnets 12a and 13a disposed in the lower stage simply by changing the magnetization direction. Therefore, the number of parts can be reduced.

  An annular magnetic gap g is formed between the annular magnet 12 and the annular magnet 13, that is, in the upper radial direction. Between the annular magnet 12a and the annular magnet 13a, that is, in the lower radial direction, an annular gap having the same size as the magnetic gap g is formed. An annular gap is also formed between the annular magnet 12 and the annular magnet 12a, that is, in the axial direction. Further, an annular gap is formed between the annular magnet 13 and the annular magnet 13a, that is, in the axial direction, approximately the same size as the gap formed between the annular magnet 12 and the annular magnet 12a. .

  In the first embodiment, the annular magnet 12 is magnetized in the radial direction. More specifically, the annular magnet 12 is magnetized so as to have an N pole on the inside and an S pole on the outside. The annular magnet 13 is also magnetized in the radial direction and is magnetized so as to have an N pole on the inside and an S pole on the outside. That is, the annular magnet 12 and the annular magnet 13 are magnetized in the same radial direction. Therefore, the direction of the magnetic flux in the magnetic gap g formed between the annular magnet 12 and the annular magnet 13 is inward.

  The annular magnet 12a is magnetized in the radial direction. More specifically, the annular magnet 12a is magnetized so as to have an S pole on the inside and an N pole on the outside. The annular magnet 13 is also magnetized in the radial direction and is magnetized so as to have an S pole on the inside and an N pole on the outside. That is, the annular magnet 12a and the annular magnet 13a are magnetized in the same radial direction. Therefore, the direction of the magnetic flux in the gap formed between the annular magnet 12a and the annular magnet 13a is outward. And the following magnetic flux directions arise in the magnetic bodies 31 and 32 which connect the annular magnets 12, 12a, 13, and 13a magnetized as described above. That is, the direction of the magnetic flux in the cylindrical magnetic body 31 connecting the annular magnet 12 and the annular magnet 12a is downward. The direction of the magnetic flux in the cylindrical magnetic body 32 connecting the annular magnet 13 and the annular magnet 13a is upward.

  A closed magnetic circuit can be configured by connecting the magnets 12, 12a, 13, 13a and the magnetic bodies 31, 32 as described above. That is, as shown by the arrow in FIG. 2, for example, the magnetic flux generated from the N pole of the annular magnet 12 is guided downward by the cylindrical magnetic flux body 31, and the annular magnets 12a and 13a are directed outward, that is, in the radial direction. And is guided upward by the cylindrical magnetic flux body 32 and flows through the annular magnets 13 and 12 inward, that is, in the radial direction. Thereby, when a current is passed through the voice coil 2, the voice coil 2 vibrates in the vertical direction. The voice coil 2 is preferably arranged only between the annular magnet 12 and the annular magnet 13. In the gap formed between the magnetic gap 2, the annular magnet 12a, and the annular magnet 13a, a magnetic flux in the opposite direction is generated. Accordingly, when a current is applied to the voice coil 2 to apply a downward force and the voice coil 2 enters the gap between the annular magnet 12a and the annular magnet 13a, an upward force is applied to the voice coil 2. Therefore, the voice coil 2 can be prevented from colliding with the circular plate A.

FIG. 4 is a cross-sectional view of a speaker device including the speaker magnetic circuit 52 according to the first embodiment. When a current is passed through the voice coil 2, the voice coil 2 vibrates in the vertical direction on the paper surface. This vibration is transmitted to the cone type diaphragm 5 via the voice coil bobbin 9. As a result, the cone type diaphragm 5 generates sound waves. The center cap 6 is attached to the cone-type diaphragm, and prevents the cone-type diaphragm from being deformed in the radial direction and the entry of dust and the like. The damper 4 holds the voice coil 2 so as to be within a predetermined magnetic field and suppresses the voice coil 2 from vibrating indefinitely. The frame 7 holds the cone type diaphragm 5. In the speaker device, the configuration other than the speaker magnetic circuit 52 may be a conventional configuration.

  According to the speaker magnetic circuit 52 according to the first embodiment described above, it is possible to reduce the weight by providing the hollow portion 20 as compared with the related art. Moreover, the speaker magnetic circuit 52 according to the first embodiment includes magnets in the upper and lower stages. Thereby, compared with the case where a magnet is arrange | positioned only in the upper stage, the magnetic flux density in the magnetic gap g can be improved.

  FIG. 5 is a cross-sectional view of the speaker magnetic circuit 53 according to the second embodiment. In addition, the detailed description is abbreviate | omitted by attaching | subjecting the same code | symbol to the same component. As shown in FIG. 5, the speaker magnetic circuit 53 according to the second embodiment has basically the same configuration as the speaker magnetic circuit 52 according to the first embodiment described above. In the speaker magnetic circuit 53 according to the second embodiment, a resin-made annular spacer B is disposed between the annular magnet 12 and the annular magnet 12a, and the annular magnet 13 is interposed between the annular magnet 13a and the annular magnet 13a. The configuration differs from the speaker magnetic circuit 52 according to the first embodiment in that an annular spacer C made of resin is arranged. Note that, in the speaker device to which the speaker magnetic circuit 53 is applied, the configuration other than the speaker magnetic circuit, that is, the diaphragm, etc., is the same as the speaker magnetic circuit 52 according to the first embodiment. Yes (see FIG. 4). Further, the point that a ferrite magnet is exemplified as a magnet and the point that polypropylene can be exemplified as a resin are the same as those of the speaker magnetic circuit 52 according to the first embodiment.

  In the speaker magnetic circuit 52 according to the first embodiment, for example, the annular magnet 12 and the cylindrical magnetic body 31 have their peripheral wall surfaces fixed with an adhesive. On the other hand, in the speaker magnetic circuit 53 according to the second embodiment, the resin-made annular spacer B is arranged on the upper surface of the annular magnet 12a arranged in the lower stage, and the annular magnet 12 is further arranged on the upper surface of the spacer B. Is arranged. The annular spacer B and the annular magnets 12 and 12a were connected by an adhesive. As a result, not only the peripheral wall surface but also the vertical direction can be reliably fixed. As a result, the annular magnets 12 and 13 arranged particularly in the upper stage can be more stably fixed. In addition, it is preferable that the radial width of the annular spacer B is approximately the same as the radial width of the annular magnet 12a and the annular magnet 12. In addition, it is preferable that the radial width of the annular spacer C is approximately the same as the radial width of the annular magnet 13 and the annular magnet 13a.

  The speaker magnetic circuit 53 according to the second embodiment described above facilitates circuit assembly in addition to the effects of the speaker magnetic circuit 52 according to the first embodiment. In addition, after the assembly is completed, the spacers can be interposed so as to be fixed more firmly than the case where the connection is made only with the magnet and the magnetic body. As a result, the stability of the speaker magnetic circuit 53 can be improved. Thereby, for example, even when a load such as an impact is applied to the speaker magnetic circuit 53 from the outside, it is possible to prevent a problem that the magnet and the magnetic body are decomposed.

FIG. 6 is a cross-sectional view of the speaker magnetic circuit 54 according to the third embodiment. In addition, the detailed description is abbreviate | omitted by attaching | subjecting the same code | symbol to the same component. As shown in FIG. 6, the speaker magnetic circuit 54 according to the third embodiment has basically the same configuration as the speaker magnetic circuit 53 according to the second embodiment described above. In the speaker magnetic circuit 54 according to the third embodiment, a resin annular spacer D is disposed between the lower surface of the annular magnet 12 a and the circular plate A, and the resin annular ring is formed on the upper surface of the annular magnet 13. The configuration differs from the speaker magnetic circuit 53 according to the second embodiment in that the spacer E is disposed. In addition, when arrange | positioning these spacers, it can fix stably by aligning the surrounding wall surface of a magnet and a spacer. Further, the speaker magnetic circuit 54 according to the third embodiment has a large area for receiving the magnetic flux of the magnet on the magnetic flux receiving side, and the speaker magnetic circuit 54 according to the third embodiment is different from the second embodiment. The configuration is different from the speaker magnetic circuit 53 according to the embodiment. Note that, in the speaker device to which the speaker magnetic circuit 53 is applied, the configuration other than the speaker magnetic circuit, that is, the diaphragm, etc., is the same as the speaker magnetic circuit 52 according to the first embodiment. Yes (see FIG. 4). Further, the point that a ferrite magnet is exemplified as a magnet and the point that polypropylene can be exemplified as a resin are the same as those of the speaker magnetic circuit 52 according to the first embodiment.

  In the speaker magnetic circuit 52 according to the first embodiment and the speaker magnetic circuit 53 according to the second embodiment, magnets having a constant radial width and height are used. On the other hand, in the magnetic circuit 54 according to the third embodiment, the magnets on the magnetic flux receiving side, that is, the annular magnet 14 and the annular magnet 15 are higher in height than the magnets on the magnetic flux releasing side. A thing was used. Thereby, the area which receives the magnetic flux of the magnet on the side that receives the magnetic flux can be made larger than the area that the magnet on the side that releases the magnetic flux emits. As a result, magnetic flux can be received more efficiently, and leakage of magnetic flux can be suppressed. Specifically, in the speaker magnetic circuit 54 according to the third embodiment, magnetic flux is transferred in the air in the gap formed between the magnetic gap g, the annular magnet 12a, and the annular magnet 15. . Therefore, the annular magnet 14 on the magnetic flux receiving side arranged in the upper stage and the magnet 15 on the magnetic flux receiving side arranged in the lower stage are higher than the magnets 13 and 12a on the magnetic flux releasing side. It was. It should be noted that by increasing the height of the side that receives the magnetic flux, it is arranged so as to protrude upward or downward with respect to the opposing magnet, but in this embodiment, the annular shape on the side that releases the magnetic flux is arranged. With respect to the magnets 13 and 12a, annular magnets 14 and 15 on the side for receiving the magnetic flux are arranged so as to protrude substantially evenly on the upper and lower sides. Thereby, the emitted magnetic flux can be received more effectively.

  The spacer D supports the annular magnet 12a. The spacer E supports a frame connected to the upper part of the speaker magnetic circuit 54 (see FIG. 4). Thereby, the stability of the speaker magnetic circuit 54 or the speaker device including the speaker magnetic circuit 54 can be improved. In addition, it is preferable that the radial width of the annular spacer C is approximately the same as the radial width of the annular magnet 12a. In addition, the radial width of the annular spacer E is preferably substantially the same as the radial width of the annular magnet 13.

  According to the speaker magnetic circuit 54 according to the third embodiment described above, leakage of magnetic flux can be suppressed in addition to the effects of the speaker magnetic circuits 52 and 53 according to the first and second embodiments. As a result, the magnetic flux density in the magnetic flux gap g can be further improved.

  FIG. 7 is a cross-sectional view of the speaker magnetic circuit 55 according to the fourth embodiment. In addition, the detailed description is abbreviate | omitted by attaching | subjecting the same code | symbol to the same component. As shown in FIG. 7, the speaker magnetic circuit 55 according to the third embodiment has basically the same configuration as the speaker magnetic circuit 53 according to the second embodiment described above. The speaker magnetic circuit 55 according to the fourth embodiment is different in that the annular magnetic body 33 is interposed in the gap formed between the annular magnet 12a and the annular magnet 13a arranged in the lower stage. The configuration differs from the speaker magnetic circuit 53 according to the second embodiment. Note that, in the speaker device to which the speaker magnetic circuit 55 is applied, for the configuration other than the speaker magnetic circuit, that is, the diaphragm and the like, the conventional diaphragm and the like are used as in the speaker magnetic circuit 52 according to the first embodiment. Yes (see FIG. 4). Further, the point that a ferrite magnet is exemplified as the magnet and the point that polypropylene can be exemplified as the resin are the same as those of the speaker magnetic circuit 52 according to the first embodiment.

  The annular magnetic body 33 guides the magnetic flux emitted from the N pole of the annular magnet 12a to the S pole of the annular magnet 13a. The radial width of the annular magnetic body 33 was the same as the radial width of the annular gap formed between the annular magnet 12a and the annular magnet 13a. The height of the annular magnetic body 33 is the same as that of the annular magnet 12a and the annular magnet 13a. Thereby, the annular magnetic body 33 and the annular magnets 12a and 13a can be closely connected. As a result, magnetic flux leakage can be suppressed.

  According to the speaker magnetic circuit 55 according to the fourth embodiment described above, magnetic flux can be transmitted more efficiently in addition to the effects of the speaker magnetic circuit 53 according to the second embodiment. In other words, magnetic flux leakage can be suppressed by interposing a magnetic substance in the gap, and as a result, the magnetic flux density of the magnetic gap g can be further improved.

  FIG. 8 is a cross-sectional view of the speaker magnetic circuit 56 according to the fifth embodiment. In addition, the detailed description is abbreviate | omitted by attaching | subjecting the same code | symbol to the same component. As shown in FIG. 8, the speaker magnetic circuit 56 according to the third embodiment has basically the same configuration as the speaker magnetic circuit 53 according to the second embodiment described above. The speaker magnetic circuit 56 according to the fifth embodiment is different in configuration from the speaker magnetic circuit 53 according to the second embodiment in that the magnet disposed in the lower stage is one of the annular magnets 16. Note that, in the speaker device to which the speaker magnetic circuit 55 is applied, for the configuration other than the speaker magnetic circuit, that is, the diaphragm and the like, the conventional diaphragm and the like are used as in the speaker magnetic circuit 52 according to the first embodiment. Yes (see FIG. 4). Further, the point that a ferrite magnet is exemplified as a magnet and the point that polypropylene can be exemplified as a resin are the same as those of the speaker magnetic circuit 52 according to the first embodiment.

  The annular magnet 16 has the same inner diameter as the inner diameter of the annular magnet 12, and the outer diameter is the same as the outer diameter of the annular magnet 13. That is, the annular magnet 16 is formed by integrally forming the annular magnets 12a and 13a and the annular magnetic body 33 arranged in the lower stage in the above-described fourth embodiment. The annular magnet 16 is magnetized in the radial direction. More specifically, the annular magnet 16 is magnetized so as to have an S pole on the inside and an N pole on the outside. By connecting the annular magnet 16 arranged in the lower stage and the annular magnets 12 and 13 arranged in the upper stage by the magnetic bodies 31 and 32, a closed magnetic circuit can be formed.

  According to the speaker magnetic circuit 56 according to the fifth embodiment described above, in addition to the effects of the speaker magnetic circuit 53 according to the second embodiment, the magnetic flux can be transmitted more efficiently. That is, an effect equivalent to that of the speaker magnetic circuit 55 according to the fourth embodiment described above can be obtained. Further, the magnet 16 arranged in the lower stage corresponds to the annular magnets 12 a and 13 a and the annular magnetic body 33 of the fourth embodiment described above. Therefore, the number of parts can be reduced as compared with the fourth embodiment.

FIG. 9 is a cross-sectional view of the speaker magnetic circuit 57 according to the sixth embodiment. In addition, the detailed description is abbreviate | omitted by attaching | subjecting the same code | symbol to the same component. As shown in FIG. 9, the speaker magnetic circuit 57 according to the sixth embodiment has basically the same configuration as the speaker magnetic circuit 56 according to the fifth embodiment described above. The speaker magnetic circuit 57 according to the sixth embodiment is similar to the fifth embodiment in that an annular groove m corresponding to the annular recess of the present invention is formed on the upper surface of the annular magnet 16a arranged at the lower stage. The configuration of the speaker magnetic circuit 56 is different. Note that, in the speaker device to which the speaker magnetic circuit 57 is applied, for the configuration other than the speaker magnetic circuit, that is, the diaphragm and the like, the conventional diaphragm and the like are used as in the speaker magnetic circuit 52 according to the first embodiment. Yes (see FIG. 4). Further, the point that a ferrite magnet is exemplified as the magnet and the point that polypropylene can be exemplified as the resin are the same as those of the speaker magnetic circuit 52 according to the first embodiment.

  As with the annular magnet 16, the annular magnet 16 a has the same inner diameter as the annular magnet 12, and the outer diameter is the same as the outer diameter of the annular magnet 13. An annular groove m is formed on the upper surface of the annular magnet 16a in the vicinity of the center of the radial width. In other words, an annular groove is formed substantially in the hanging direction of the magnetic gap g. The annular magnet 16a is preferably a bonded magnet. By using the bond magnet, the annular groove m can be easily molded. The annular magnet 16a is magnetized so as to have an S pole on the inner side and an N pole on the outer side, like the annular magnet 16 according to the fifth embodiment.

  According to the speaker magnetic circuit 57 according to the sixth embodiment described above, in addition to the effects of the speaker magnetic circuit 56 according to the fifth embodiment, the lower part of the voice coil 2 inserted into the magnetic gap g is in vibration. Can be prevented from contacting the annular magnet 16a.

  FIG. 10 is a cross-sectional view of the speaker magnetic circuit 58 according to the seventh embodiment. In addition, the detailed description is abbreviate | omitted by attaching | subjecting the same code | symbol to the same component. As shown in FIG. 10, the speaker magnetic circuit 57 according to the seventh embodiment has speaker magnets according to the first embodiment in that it includes annular magnets 12 and 13 and cylindrical magnetic flux bodies 31 and 32. It matches the circuit 52. The speaker magnetic circuit 58 according to the seventh embodiment includes an annular magnet 17a, an annular magnet 17b disposed outside the annular magnet 17a, a lower portion of the annular magnet 17a, and an annular magnet 17b. It differs from the speaker magnetic circuit 52 according to the first embodiment in that it has a magnetic body 34 that connects the lower part. Note that, in the speaker device to which the speaker magnetic circuit 58 is applied, for the configuration other than the speaker magnetic circuit, that is, the diaphragm and the like, the conventional diaphragm and the like are used similarly to the speaker magnetic circuit 52 according to the first embodiment. Yes (see FIG. 4). Further, the point that the magnet is exemplified as the magnet is the same as that of the speaker magnetic circuit 52 according to the first embodiment.

  The annular magnet 17a is magnetized in the axial direction. More specifically, the annular magnet 17a is magnetized so as to have an S pole on the upper side and an N pole on the lower side. The radial width of the annular magnet 17 a is formed to be approximately the same as the radial width of the cylindrical magnetic body 31. The annular magnet 17b is magnetized in the axial direction. More specifically, the annular magnet 17b is magnetized so as to have an N pole on the upper side and an S pole on the lower side. The radial width of the annular magnet 17 b is formed to be approximately the same as the radial width of the cylindrical magnetic body 32. Thus, leakage of magnetic flux can be suppressed by making the cylindrical magnetic bodies 31 and 32 and the peripheral wall surfaces of the annular magnets 17a and 17b coincide.

  The magnetic body 34 includes a cylindrical portion 34a having the same diameter as the cylindrical magnetic body 31, a cylindrical portion 34b disposed around the cylindrical portion 34 and having the same diameter as the cylindrical magnetic body 32, and a lower portion and a cylindrical portion of the cylindrical portion 34a. And a donut disk part 34c to which the lower part of the part 34b is connected. In addition, the cylinder part 34, the cylinder part 34a, and the donut disk part 34c are integrally formed. FIG. 11 is a perspective view showing the magnetic body 34. By connecting the magnetic body 34 having such a shape to the lower part of the annular magnet 17a and the lower part of the annular magnet 17b, a closed speaker magnetic circuit can be formed.

  According to the speaker magnetic circuit 58 according to the seventh embodiment described above, the hollow portion 20 is provided, so that the weight can be reduced as compared with the related art. Further, the speaker magnetic circuit 58 according to the seventh embodiment includes annular magnets 17 a and 17 b between the cylindrical magnetic body 31 and the magnetic body 34. Thereby, compared with the case where a magnet is arrange | positioned only in the upper stage, the magnetic flux density in the magnetic gap g can be improved.

  FIG. 12 is a cross-sectional view of the speaker magnetic circuit 59 according to the eighth embodiment. As shown in FIG. 12, the speaker magnetic circuit 59 according to the eighth embodiment includes a magnet 18a having a ring portion in part, a magnet 18b having a ring portion in part disposed around the magnet 18a, A magnet 18c connected to the lower part of the magnet 18a and the magnet 18b and having a donut disk part in part.

  The magnet 18a has an annular portion 18a1 and a tubular portion 18a2 connected to the inner lower portion of the annular portion 18a1. The annular portion 18a1 and the cylindrical portion 18a2 are integrally formed. The annular portion 18a1 is magnetized in the radial direction, and the cylindrical portion 18a2 is magnetized in the axial direction. More specifically, the annular portion 18a1 is magnetized so that the outer side becomes the S pole, and the cylindrical portion 18a2 is magnetized so that the lower side becomes the N pole.

  The magnet 18b has an annular portion 18b1 and a cylindrical portion 18b2 connected to the outer lower portion of the annular portion 18b1. The annular portion 18b1 and the cylindrical portion 18b2 are integrally formed. The annular portion 18b1 is magnetized in the radial direction, and the cylindrical portion 18b2 is magnetized in the axial direction. More specifically, the annular portion 18b1 is magnetized so that the inner side becomes the N pole, and the cylindrical portion 18b2 is magnetized so that the lower side becomes the S pole.

  The magnet 18c is disposed around the cylindrical portion 18c1 having the same diameter as the cylindrical portion 18a2, and the cylindrical portion 18c2 having the same diameter as the cylindrical portion 18b2, and the lower portion of the cylindrical portion 18c1 and the lower portion of the cylindrical portion 18c2 are connected. A donut disk portion 18c3. In addition, the cylinder part 18c1, the cylinder part 18c2, and the donut disk part 18c3 are integrally formed. The cylinder portion 18c1 is magnetized in the axial direction, and the cylinder portion 18c2 is also magnetized in the axial direction. More specifically, the cylinder portion 18c1 is magnetized so that the upper side becomes the S pole, and the cylinder portion 18c2 is magnetized so that the upper side becomes the N pole. The cylindrical portions 18a1, 18a2, 18c1, and 18c2 all have the same radial width. Thereby, the leakage of the magnetic flux from a connection part can be suppressed.

  FIG. 13 is an exploded perspective view of the speaker magnetic circuit 59 according to the eighth embodiment. As shown in the figure, the speaker magnetic circuit 59 according to the eighth embodiment can be configured by connecting three magnets of a magnet 18a, a magnet 18b, and a magnet 18c. An adhesive can be used for bonding these magnets. Moreover, it is preferable to use a bond magnet for these three magnets. Molding is facilitated by using a bonded magnet.

  According to the speaker magnetic circuit 59 according to the eighth embodiment described above, the weight can be reduced as compared with the conventional case by including the hollow portion 20 and using a magnet having a lower density than the magnetic body instead of the magnetic body. Can do. The bond magnet has a lower density than the magnetic body. Therefore, when a bonded magnet is used, the speaker magnetic circuit 59 can be more effectively reduced in weight. In the speaker magnetic circuit 59 according to the eighth embodiment, the speaker magnetic circuit is entirely made of magnets. Therefore, the magnetic flux density in the magnetic gap g can be improved as compared with the case where the magnet is disposed only in the upper stage.

  Although the preferred embodiments of the present invention have been described above, the speaker magnetic circuit according to the present invention is not limited to these, and can include combinations thereof as much as possible.

It is sectional drawing of the conventional common speaker magnetic circuit 50. FIG. It is sectional drawing of the speaker magnetic circuit 52 which concerns on 1st Embodiment. It is a top view of the speaker magnetic circuit 52 which concerns on 1st Embodiment. It is sectional drawing of a speaker apparatus provided with the speaker magnetic circuit 52 which concerns on 1st Embodiment. It is sectional drawing of the speaker magnetic circuit 53 which concerns on 2nd Embodiment. It is sectional drawing of the speaker magnetic circuit 54 which concerns on 3rd Embodiment. It is sectional drawing of the speaker magnetic circuit 55 which concerns on 4th Embodiment. It is sectional drawing of the speaker magnetic circuit 56 which concerns on 5th Embodiment. It is sectional drawing of the speaker magnetic circuit 57 which concerns on 6th Embodiment. It is sectional drawing of the speaker magnetic circuit 58 which concerns on 7th Embodiment. 3 is a perspective view showing a magnetic body 34. FIG. It is sectional drawing of the speaker magnetic circuit 59 which concerns on 8th Embodiment. It is a disassembled perspective view of the speaker magnetic circuit 59 which concerns on 8th Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Yoke 2 ... Voice coil 4 ... Damper 5 ... Cone-type diaphragm 6 ... Center cap 7 ... Frame 8 ... Plate 9 ... Voice coil bobbin 10,11, 12, 12a, 13, 13a, 14, 15, 16, 17a, 17b, 18a, 18b, 18c ... magnets 31, 32, 33, 34 ... magnetic body 50 ... conventional general speaker magnetism Circuit 51... Lighter speaker magnetic circuit A... Circular plate B, C, D, E.

Claims (7)

An annular first magnet magnetized in the radial direction and a magnetic gap into which a voice coil for transmitting vibration to the speaker diaphragm is inserted around the outer peripheral wall surface of the first magnet. A first magnetic flux generator having a second magnet that is annular and radially magnetized,
A second magnetic flux generator having a magnet, disposed below the first magnetic flux generator,
At least the inner peripheral wall surface of the first magnet, the outer peripheral wall surface of the second magnet, and the magnet of the second magnetic flux generating unit, and the first magnetic flux generating unit and the second magnetic flux generating unit; And a magnetic part that transmits magnetic flux between the speaker magnetic circuit and the speaker magnetic circuit. The magnetic body portion includes a cylindrical first magnetic body and a cylindrical second magnetic body formed around an outer peripheral wall surface of the first magnetic body,
The second magnetic flux generator is annular and includes a third magnet magnetized in a radial direction so as to be opposite to the direction of the magnetic flux generated from the first magnet, and the third magnet A fourth magnet which is arranged so as to form a gap around the outer peripheral wall surface and which is annularly magnetized in the radial direction so as to be opposite to the direction of the magnetic flux generated from the second magnet; Have
The first magnet is connected to an upper portion of an outer peripheral wall surface of the first magnetic body,
The second magnet is connected to an upper portion of the inner peripheral wall surface of the second magnetic body,
The third magnet is connected to a lower portion of the outer peripheral wall surface of the first magnetic body,
The fourth magnet is connected to a lower portion of the inner peripheral wall surface of the second magnetic body,
The direction of the magnetic flux in the gap between the third magnet and the fourth magnet is opposite to the direction of the magnetic flux in the magnetic gap between the first magnet and the second magnet. The speaker magnetic circuit according to claim 1, wherein Of the first magnet and the second magnet, the area receiving the magnetic flux of the magnet on the magnetic flux receiving side is formed large,
The speaker magnetic circuit according to claim 2, wherein an area for receiving a magnetic flux of a magnet on a magnetic flux receiving side of the third magnet and the fourth magnet is formed large. The magnetic body portion includes a cylindrical first magnetic body and a cylindrical second magnetic body formed around an outer peripheral wall surface of the first magnetic body,
The second magnetic flux generation unit has a fifth magnet that is annular and magnetized in the radial direction so as to be opposite to the direction of the magnetic flux generated from the first magnet,
The first magnet is connected to an upper portion of an outer peripheral wall surface of the first magnetic body,
The second magnet is connected to an upper portion of the inner peripheral wall surface of the second magnetic body,
The speaker magnetic circuit according to claim 1, wherein the fifth magnet is connected to a lower portion of an outer peripheral wall surface of the first magnetic body and a lower portion of an inner peripheral wall surface of the second magnetic body.   The speaker magnetic circuit according to claim 4, wherein an annular recess is formed on an upper surface of the fifth magnet and below the magnetic gap. The magnetic body portion includes a cylindrical first magnetic body connected to the inner peripheral wall surface of the first magnet, and a cylindrical second magnetic body connected to the outer peripheral wall surface of the second magnet. And a donut disk part connected to the second magnetic flux generation part,
The second magnetic flux generation section has an annular shape that is approximately the same diameter as the first magnetic body, and is approximately the same diameter as the sixth magnet magnetized in the axial direction and the second magnetic body. And a seventh magnet magnetized in the axial direction so as to be opposite to the direction of the magnetic flux generated from the sixth magnet,
The sixth magnet is disposed between the first magnetic body and the donut disk part,
The speaker magnetic circuit according to claim 1, wherein the seventh magnet is disposed between the second magnetic body and the donut disk portion. A magnet having a first annular portion and a first cylindrical portion connected to an inner lower surface of the first annular portion, wherein the first annular portion is magnetized in a radial direction, The cylindrical portion is an eighth magnet magnetized in the axial direction and does not oppose the magnetic flux generated from the first annular portion;
A second annular portion disposed around the outer peripheral wall surface of the first annular portion so as to form a magnetic gap into which a voice coil that transmits vibration to a diaphragm of the speaker is inserted; A second cylindrical portion connected to an outer lower surface of the annular portion, wherein the second annular portion is magnetized in a radial direction, and the second cylindrical portion is formed from the first cylindrical portion. A ninth magnet that is magnetized in a direction opposite to the generated magnetic flux and in a direction that does not oppose the magnetic flux generated from the second annular portion;
A third tube portion having substantially the same diameter as the first tube portion; a fourth tube portion having substantially the same diameter as the second tube portion; a lower portion of the third tube portion; and the fourth tube. A magnet having a donut disk part to which a lower part of the part is connected, wherein the third cylinder part is magnetized in a direction coaxial with a direction of magnetic flux generated from the first cylinder part, and the fourth cylinder The portion is magnetized in the same direction as the direction of the magnetic flux generated from the second cylindrical portion, and the donut disk portion is magnetized in the radial direction so as to be opposite to the direction of the magnetic flux generated from the first annular portion. A speaker magnetic circuit comprising a tenth magnet that is magnetized.

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