JP2006074006A - Magnetic element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a magnetic element in which productivity is superior and cost reduction is enabled while attaining a desired property. <P>SOLUTION: The magnetic element is provided with a first coil 50 to which a signal is inputted, a second coil 60 to which the signal inputted to the first coil 50 is transmitted, a first core 20 having a first columnar leg portion 26 on which the first coil 50 is wound and first peripheral wall portions 22, 23, 24 arranged on the periphery of the first columnar leg portion 26, and a second core 30 having a second columnar leg portion 36 on which the second coil 60 is wound and second peripheral wall portions 32, 33 34 arranged on the periphery of the second columnar leg portion 36. The relative permeability of the first core 20 is set higher than the relative permeability of the second core 30, the first columnar leg portion 26 and the second columnar leg portion 36 abut on each other, and the first peripheral wall portions 22, 23, 24 and the second peripheral wall portions 32, 33, 34 abut on each other. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a magnetic element such as a transformer used as a bandpass filter, for example.

  Some transformers, which are a kind of magnetic element, function as a so-called band-pass filter (band filter) that passes only signals in a desired frequency band (for example, around 13 Khz). In this type of transformer, it is necessary to adjust the impedance to a desired value, and among the signals input to the primary side, a high frequency signal having a predetermined frequency or more and a low frequency signal having a predetermined frequency or less are used. It is required to have a characteristic that attenuates on the secondary side.

  By the way, the impedance is proportional to the inductance, and it becomes difficult for alternating current to flow at a high frequency, and an attenuation effect of the high-frequency signal can be obtained. Therefore, when obtaining the above-described characteristics in the transformer, at present, a configuration using two cores made of a material having a high μ with a relative permeability (μ) of 10,000 or more is employed. In the following description, each of the two cores is referred to as a first core and a second core.

  Here, the first core and the second core are arranged to face each other, but the magnetic path formed between the first core and the second core is a gap where no magnetic material exists. A certain gap (also referred to as an air gap) is provided. The presence of such a gap makes it possible to attenuate the signal on the low frequency side.

  For example, in the EP core, this gap is usually provided between the column base of the first core and the column base of the second core. Since it has been found that the smaller the gap (the smaller the gap), the better characteristics can be obtained. At present, some of the gaps have a size of about 22 μm. A configuration of a magnetic element having such a gap is disclosed in Patent Document 1.

  In addition, a tape member made of resin or the like is attached to the butt portion between the first core and the second core, and the thickness of the tape member is between the first core and the second core. There are also configurations that ensure a gap. In this configuration, the tape member exists at the boundary between the first core and the second core, and the first core and the second core are joined to each other via the tape member.

  Furthermore, as another method of obtaining a transformer having an inductance having a desired value, the first core and the second core are formed by using a material having a relative permeability (μ) of about 5000, and the first core and the second core are formed. There is one that attaches two cores without a gap.

Japanese Patent Laid-Open No. 2003-31422 (see abstract, FIG. 1, FIG. 5 to FIG. 8)

  By the way, among the above-mentioned transformers, when a material having a high relative permeability is combined and a narrow gap is formed, there is a problem that it is difficult to form the narrow gap. That is, for example, when a very narrow gap such as 22 μm is formed, it is difficult to accurately manage the dimensional accuracy. Also, a matching error or the like occurs when the first core and the second core are matched. For this reason, it is difficult to provide a desired narrow gap between the first core and the second core. Further, when such a high-precision narrow gap is formed, it is necessary to improve accuracy, so that the processing cost is increased. Since it is necessary to form a narrow gap, there is also a problem that it takes time to produce a transformer and the production efficiency deteriorates.

  Further, in the configuration in which the tape member is interposed between the first core and the second core, there is a problem that the tape member is melted by heating. That is, when a transformer is mounted on a substrate, there are processes involving heating such as soldering by reflow. In such a heating process, the thin film tape member having the above-mentioned narrow gap thickness can be easily unwound. End up. As described above, when the tape member is melted, the gap dimension cannot be accurately managed, and desired characteristics cannot be obtained.

  Further, when the first core and the second core are formed of a material having a relative permeability of about 5000, there is no gap, so the high frequency signal is not attenuated, and the high frequency is picked up as noise in the secondary coil. End up. That is, when the first core and the second core are made of a material having a relative permeability of about 5000, there is a problem that the characteristics as a bandpass filter are inferior and the function is not exhibited.

  As described above, at present, it is difficult to form a transformer that has desired characteristics, such as a transformer having a narrow gap, and that combines elements such as high productivity and cost reduction. ing.

  The present invention has been made on the basis of the above circumstances, and the object of the present invention is to provide a magnetic element capable of obtaining desired characteristics but having good productivity and cost reduction. It is intended to provide.

  In order to solve the above-described problems, the present invention provides a first core, a second core that contacts the first core, a signal, and at least one of the first core and the second core. A first core having a relative permeability higher than that of the second core and between the first core and the second core. The closed magnetic circuit is formed in the state where there is no magnetic gap.

  In such a configuration, a closed magnetic circuit is formed between the first core and the second core in a state where no magnetic gap exists. Here, since the first core has a higher relative magnetic permeability than the second core, a magnetic gap is provided between the first core and the second core as in the prior art. Even if it is not, desired characteristics can be obtained with the entire magnetic element. In other words, the first core having a high relative permeability can attenuate a high-frequency signal, and the second core having a low relative permeability can be used to match the effective permeability and help to attenuate the low-frequency signal. It becomes. For this reason, it is possible to obtain the same characteristics as a magnetic element having a narrow gap.

  In another aspect of the invention, a first coil to which a signal is input, a second coil to which a signal input to the first coil is transmitted, and a first column around which the first coil is wound. A first core having a first peripheral wall portion disposed around the leg portion and the first column base portion; a second column base portion around which the second coil is wound; and the second column A second core having a second peripheral wall portion disposed around the leg portion, and the relative permeability of the first core is higher than the relative permeability of the second core. In addition, the first column base and the second column base are in contact with each other, and the first peripheral wall and the second peripheral wall are in contact with each other.

  When configured in this manner, the first column base and the second column base, and the first peripheral wall and the second peripheral wall are in contact with each other without a gap between them. Become. In this case, if the relative permeability of each of the first core and the second core is adjusted in a state where the first core has a higher relative permeability than the second core, the conventional core can be adjusted. In addition, even if no gap is provided between the first core and the second core, desired characteristics can be obtained with the entire magnetic element. That is, the first core having a high relative permeability can attenuate a high frequency signal, and the second core having a low relative permeability can be used to attenuate a low frequency signal. As a bandpass filter, It is possible to obtain the same characteristics as a magnetic element having a narrow gap.

  In addition, since it is not necessary to provide a narrow gap between the first core and the second core in order to obtain desired characteristics, the number of processes can be reduced and productivity can be improved. In addition, since the number of processes is reduced, production costs can be suppressed. Further, there is no need to interpose a tape member to form a narrow gap between the first core and the second core. Therefore, it is possible to prevent a problem that the tape member is melted by heat at the time of mounting such as reflow and the size management of the gap cannot be performed accurately.

  In another invention, in addition to the above-described invention, the relative permeability of the first core is provided in the range of 4 to 100 times the relative permeability of the second core. It is. In the case of such a configuration, the difference in relative permeability between the first core and the second core is increased, which is equivalent to the conventional configuration in which a narrow gap exists between the Hiμ materials. A bandpass filter having characteristics can be obtained.

  Furthermore, in addition to the above-described inventions, in another invention, the relative permeability of the first core is in the range of 2000 to 30000, and the relative permeability of the second core is 20 to 2000. It is within the range. When configured in this way, the difference in relative permeability between the first core and the second core can be made large, and a conventional narrow gap exists between the Hiμ materials. It is possible to obtain a bandpass filter having the same characteristics as the above.

  Furthermore, in addition to the above-described inventions, the first core is made of a Mn-based magnetic member, and the second core is made of a Ni-based magnetic member. is there. When configured in this way, the first core has a high relative magnetic permeability that the Mn-based magnetic member has, and the second core has the second core that the Ni-based magnetic member has, the first core. It becomes a state provided with a relative magnetic permeability lower than that of the core. Therefore, it is possible to obtain a band-pass filter having the same characteristics as a conventional structure in which a narrow gap exists between Hiμ materials.

  According to another invention, in addition to the above-described inventions, the first core and the second core have a symmetrical shape with respect to a portion in contact with each other. In this case, since the first core and the second core have the same area, the boundary portions of the first core and the second core can be brought into contact with each other without a stepped portion, and magnetic flux leakage to the outside can be achieved. Can be reduced. In addition, positioning becomes easier when the first core and the second core come into contact with each other.

  Furthermore, in another invention, in addition to the above-mentioned inventions, the first core and the second core form an EP core. When configured in this way, a bandpass filter having excellent space efficiency can be obtained.

  According to another invention, in addition to the above-described inventions, a signal transmitted from the first coil to the second coil due to a difference in relative permeability between the first core and the second core. Among these frequencies, the signal functions as a bandpass filter for attenuating the amplitude of a signal having a frequency outside a specific band below a threshold value.

  In such a configuration, the magnetic element functions as a band-pass filter, so that a signal in a specific frequency band among signals input to the first coil can be satisfactorily transmitted to the second coil. However, in the case of a signal having a frequency outside the specific frequency band, when the signal input to the first coil is transmitted to the second coil, the signal can be greatly attenuated to an amplitude equal to or less than the threshold value.

  According to the present invention, in a magnetic element capable of obtaining desired characteristics, the productivity can be improved and the cost can be reduced.

(First embodiment)
Hereinafter, a transformer 10 as a magnetic element according to a first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a perspective view showing the overall configuration of the transformer 10. FIG. 2 is an exploded perspective view showing the configuration of the transformer 10. FIG. 3 is a front view showing the shape of the first core 20 or the second core 30 of the transformer 10. FIG. 4 is a side sectional view showing the internal configuration of the transformer 10.

  As shown in FIGS. 2 and 4, the transformer 10 in the present embodiment includes a first core 20, a second core 30, a coil bobbin 40, a primary winding 50, and a secondary winding 60. It is a major component. Among these, the first core 20 and the second core 30 are symmetrical. Note that the transformer 10 constituted by these members is a magnetic element having a so-called EP core.

  As shown in FIGS. 2 and 3, the first core 20 is a core member having a box shape in a state where the two surfaces of the board plane side to be mounted and the side facing the second core 30 are open. is there. The first core 20 is provided with a recessed fitting portion 21. The recessed fitting portion 21 is surrounded by an upper wall 22 facing the substrate plane side, a side bottom wall 23 facing the second core 30, and two peripheral walls 24 a and 24 b along the central axis of the first core 20. Is formed. The upper wall 22, the side bottom wall 23, and the peripheral walls 24a and 24b correspond to the first peripheral wall portion.

  In the following description, among the first cores 20, the board plane side (mounting terminal side to be described later) to be mounted is the lower side, and the upper wall 22 side is the upper side. In addition, a surface of the first core 20 that is abutted against the second core 30 is referred to as a facing surface 25.

  As shown in FIGS. 3 and 4, the recessed fitting portion 21 is an inverted U-shaped recessed portion having a predetermined depth. Therefore, the inner wall surfaces of the peripheral walls 24a and 24b constituting the recessed fitting portion 21 are directed upward from the open lower side and are substantially parallel to the outer wall surfaces of the peripheral walls 24a and 24b, but the upper front shape Has a substantially semicircular shape. Accordingly, the substantially semicircular portion is provided so as to be separated from the peripheral walls 24a and 24b as it goes upward.

  Further, the recessed fitting portion 21 is provided with a column base portion 26 (corresponding to the first column base portion). The column base portion 26 is provided in a columnar shape in the present embodiment. Further, the column base portion 26 protrudes from the side bottom wall 23 toward the facing surface 25 side so as to be substantially parallel to the upper end surface of the upper wall 22. In addition, the protruding height of the column base 26 is substantially the same height as the facing surface 25 described above. Therefore, even when the first core 20 and the second core 30 are brought into contact with each other, no gap is formed between the column base 26 and a column base 36 described later.

  Also, the second core 30 has the same configuration as the first core 20 described above. Therefore, detailed description on the structure is omitted. In the following description, with respect to the reference numerals of the respective parts in the second core 20, the recessed fitting part 31, the upper wall 32, the side bottom wall 33, the peripheral walls 34 a and 34 b, the facing surface 35, the column base part 36 ( 2). The upper wall 32, the side bottom wall 33, and the peripheral walls 34a and 34b correspond to the second peripheral wall portion.

  Here, the material of the first core 20 is provided with a higher relative magnetic permeability (μ) than the material of the second core 30. In the present embodiment, the first core 20 is made of Mn-based ferrite having a relative magnetic permeability of about 10,000. Such a material having a relative permeability of about 10,000 or more is generally called a Hiμ (high mu) material.

  In addition, the relative magnetic permeability with which the 1st core 20 is provided is not restricted to about 10,000, and should just exist in the range of 2000-30000. However, it is preferable that the relative permeability of the first core 20 is approximately 5000 or more (for example, when a material such as amorphous material is used), and the relative permeability of the first core 20 is approximately. If it is 10,000 or more, it becomes more preferable.

  On the other hand, the material of the second core 30 is provided with a lower relative permeability than the material of the first core 20. Here, the relative permeability of the first core 20 is preferably provided in the range of 4 to 100 times the relative permeability of the second core 30.

  In the present embodiment, the relative magnetic permeability of the material of the second core 30 may be in the range of about 20 to about 2000. A more preferable range of the relative magnetic permeability is about 20 to about 1000. Furthermore, as will be described later, the relative permeability of the second core 30 is set to 10000 as the relative permeability of the first core 20, and the relative permeability of the second core 30 to 100, 400, Experiments were conducted as 850, and all of them obtained characteristics equivalent to those of a conventional transformer having a narrow gap (including a transformer that forms a narrow gap by a tape member). Considering this point, when the relative permeability is in the range of 100 to 850, characteristics equivalent to those of the conventional transformer can be obtained.

  Note that when the relative permeability of the first core 20 is approximately 10,000 and the relative permeability of the second core 30 is 850, the characteristics of the transformer 10 correspond to a configuration in which a gap of 18 μm exists. . Moreover, Ni type ferrite is mentioned as a material with a low relative magnetic permeability.

  A coil bobbin 40 is attached to the above-described column base portions 26 and 36. The coil bobbin 40 is made of an insulating material such as resin. As shown in FIG. 2, the coil bobbin 40 includes a winding portion 41 that winds the primary winding 50 and the secondary winding 60, and a flange portion 42 that is provided integrally with the winding portion 41. It has the 1st terminal block 43a and the 2nd terminal block 43b which were provided integrally.

  The winding part 41 is provided in a substantially cylindrical shape, and flanges 42 are provided at both ends of the winding part 41 in the axial direction of the substantially cylindrical part. That is, the winding part of the primary winding 50 and the secondary winding 60 is defined in the coil bobbin 40 due to the presence of the flange portion 42. In addition, the collar portion 42 is provided with a substantially U-shaped appearance, and corresponds to the appearance shape of the recessed fitting portion 21 described above. In addition, a through hole 44 is provided so as to penetrate the winding portion 41, and the column base portions 26 and 36 are inserted into the through hole 44.

  A conductive wire such as enamel is wound around the winding portion 41, for example. Accordingly, the primary winding 50 (corresponding to the first coil) on the column base 26 is a signal input side, and the secondary winding 60 (the second winding 60 is a signal output side) on the column base 36. Corresponding to the coil) is formed. With the primary winding 50 and the secondary winding 60 wound around the winding portion 41, the column base portions 26 and 36 are inserted into the through holes 44 of the coil bobbin 40, and the first core 20 and the second winding 60 are inserted. Cores 30 of each other are abutted against each other. After the butting, the first core 20 and the second core 30 are joined via an adhesive or a pressing member (not shown), for example.

  The primary winding 50 and the secondary winding 60 may be round wires having a circular cross section. However, the primary winding 50 and the secondary winding 60 may be formed of a conductive wire having a cross-sectional shape other than the round wire such as a square wire. May be formed.

  In addition, the coil bobbin 40 is provided with a first terminal block 43 a and a second terminal block 43 b so as to be integrated with the flange portion 42. The first terminal block 43a and the second terminal block 43b are attached to the upper portion of the U shape formed by the flange portion 42 (in FIG. 4, since it has an inverted U shape, the lower portion of the flange portion 42). In addition, it protrudes toward the non-facing surface side of the flange portion 42 (that is, the side where the first terminal block 43a and the second terminal block 43b move away from each other) so as not to reach the winding portion 41. . The first core 20 is mounted on the first terminal block 43a, and the second core 30 is mounted on the second terminal block 43b.

  The first terminal block 43a and the second terminal block 43b are provided with a plurality of terminals (binding terminal 45 and mounting terminal 46). Among these, the binding terminal 45 is connected to one end side or the other end side of the primary winding 50 or the secondary winding 60 wound around the winding portion 41. Therefore, the height position of the binding terminal 45 is provided higher than the height position of the mounting terminal 46. The mounting terminal 46 is mounted on the circuit board 70.

  In the present embodiment, two windings of the primary winding 50 and the secondary winding 60 are wound around the winding portion 41. However, the number of windings wound around the winding portion 41 is not limited to two and may be three or more.

  The experimental results of the characteristics of the transformer 10 having the above configuration are shown in FIGS. 5 to 7, the attenuation rate (dB) of the transformer 10 is indicated on the vertical axis, and the frequency (Hz) is indicated on the horizontal axis. In these experimental results, a signal having a frequency of 1 kHz to 10 MHz is given to the primary winding 50.

  In FIG. 5, the relative permeability of the first core 20 and the second core 30 is both 10000, and a tape member is sandwiched between the first core 20 and the second core 30. The characteristics of the transformer 10 in which the relative permeability of the first core 20 is 10,000 and the relative permeability of the second core 30 is 100 are indicated by solid lines.

  The characteristics of the transformer 10 shown in FIG. 5 approximate the characteristics of the transformer in which the tape member is held. In FIG. 5, the transformer 10 is approximately -3 dB near 50 kHz, and has the same characteristics as the conventional transformer. It should be noted that variation occurs on the lower frequency side than 13 kHz, and accurate data could not be obtained by the measuring device. However, when taking the average value of the variable attenuation rate, the conventional tape member is sandwiched between the transformer 10 and the transformer 10. As in the case of the transformer, the low frequency signal is attenuated as the frequency decreases.

  Various threshold values for the attenuation factor as the high frequency filter can be set. For example, it may be −3 dB as described above, or any other value.

  In FIG. 6, the relative permeability of the first core 20 and the second core 30 is both 10000, and the tape member is sandwiched between the first core 20 and the second core 30. The characteristic of the transformer 10 is indicated by a broken line, and the characteristic of the transformer 10 in which the relative permeability of the first core 20 is 10,000 and the relative permeability of the second core 30 is 400 is indicated by a solid line.

  The characteristics of the transformer 10 shown in FIG. 6 are also similar to the characteristics of the transformer in which the tape member is sandwiched. The transformer 10 is approximately −3 dB in the vicinity of 50 kHz, and has the same characteristics as the conventional transformer. . In the transformer 10 shown in FIG. 6 as well, variation occurs on the lower frequency side than 13 kHz, and accurate data could not be obtained by the measuring device, but when taking the average value of the variation attenuation rate, It can be seen that in the transformer 10, as in the case of the transformer in which the conventional tape member is sandwiched, the signal on the low frequency side is attenuated as the frequency is lowered.

  Further, in FIG. 7, the relative permeability of the first core 20 and the second core 30 is both 10000, and the tape member is sandwiched between the first core 20 and the second core 30. The characteristic of the transformer 10 is indicated by a broken line, and the characteristic of the transformer 10 in which the relative permeability of the first core 20 is 10,000 and the relative permeability of the second core 30 is 850 is indicated by a solid line.

  The characteristics of the transformer 10 shown in FIG. 7 are also similar to the characteristics of the transformer in which the tape member is sandwiched. The transformer 10 is approximately −3 dB in the vicinity of 50 kHz, and has the same characteristics as the conventional transformer. . In the transformer 10 shown in FIG. 7 as well, variations occur on the lower frequency side than 13 kHz, and accurate data could not be obtained by the measuring device, but when taking the average value of the variation attenuation rate, It can be seen that in the transformer 10, as in the case of the transformer in which the conventional tape member is sandwiched, the signal on the low frequency side is attenuated as the frequency is lowered.

  From the above experimental results, when the first core 20 is made of a Hiμ material having a high relative magnetic permeability, the second core 30 is made of a material having a low relative magnetic permeability, and a configuration in which both are abutted is adopted, Both the second cores 30 are made of Hiμ material, and can have the same characteristics as the configuration of the conventional transformer 10 having a narrow gap between the column base 26 and the column base 36. That is, when viewed from the average value, the transformer 10 attenuates the signal in the low frequency region.

  According to the transformer 10 having such a configuration, the first core 20 is provided with a higher relative permeability than the second core 30, and the column base 26, the column base 36, and the first peripheral wall are provided. It will be in the state which contact | abuts without a gap mutually between a part and a 2nd surrounding wall part.

  In this case, if the relative permeability is set in the state where the first core 20 has a higher relative permeability than the second core 30, the first core 20 and the second core 30 are set. Even if a gap is not provided between them, the entire transformer 10 can obtain characteristics (desired characteristics) equivalent to those of a conventional transformer having a narrow gap. That is, the low-frequency signal can be attenuated by the presence of the second core 30 having a low relative permeability.

  Further, since a material having a high relative permeability is used as the first core 20, the transformer 10 can be set to a high impedance. Furthermore, since the relative permeability of the second core 30 is lower than that of the first core 20, the loss can be reduced as compared with the conventional configuration in which the two cores use a material having a high relative permeability. Is also possible.

  Further, it is not necessary to provide a narrow gap (narrow gap) between the first core 20 and the second core 30 in order to obtain desired characteristics. As a result, it is possible to reduce the steps required for processing the narrow gap, and it is possible to increase productivity. In addition, since it is not necessary to process a narrow gap, it is possible to reduce the cost required for the processing. In particular, since a very narrow gap of about 22 μm is formed at present, the productivity increase effect and the cost reduction effect by eliminating the gap increase.

  Further, unlike the prior art, there is no need to interpose a tape member in order to form a narrow gap between the first core 20 and the second core 30. Therefore, it is possible to prevent a problem that the tape member is melted by heat at the time of mounting such as reflow and the size management of the gap cannot be performed accurately. That is, since no tape member is interposed, it is possible to perform reflowing and the like without problems, and it is not necessary to accurately manage the size of the narrow gap.

  In the present embodiment, the relative permeability of the first core 20 is provided in the range of 4 to 100 times the relative permeability of the second core 30. For this reason, the difference in the relative magnetic permeability between the first core 20 and the second core 30 becomes large, and a band having the same characteristics as a conventional structure in which a narrow gap exists between Hiμ materials. A path filter can be obtained.

  Furthermore, in the present embodiment, the relative permeability of the first core 20 is in the range of 2000 to 30000, and the relative permeability of the second core 30 is in the range of 20 to 2000. . In this case, the difference in relative permeability between the first core 20 and the second core 30 can be made large, and characteristics equivalent to the conventional configuration in which a narrow gap exists between the Hiμ materials. It is possible to obtain a bandpass filter comprising

  The first core 20 is made of a Mn-based magnetic member having a high relative magnetic permeability of about 10,000 or the like, and the second core 30 has a lower relative magnetic permeability than that of the Mn-based magnetic member. A Ni-based magnetic member is used as the material. For this reason, due to the difference in relative permeability between the first core 20 and the second core 30, the bandpass filter has the same characteristics as a conventional configuration in which a narrow gap exists between Hiμ materials. It becomes possible to prepare.

  Furthermore, the first core 20 and the second core 30 have a symmetric shape with respect to a portion where they are in contact with each other. When configured in this manner, the first core 20 and the second core 30 have the same area, so that the boundary portions can be brought into contact with each other without a stepped portion, and magnetic flux leakage to the outside can be achieved. Can be reduced. In addition, when the first core 20 and the second core 30 come into contact with each other, positioning is facilitated.

  The first core 20 and the second core 30 form an EP core. When comprised in this way, the primary winding 50 and the secondary winding 60 can be functioned as a band pass filter excellent in space efficiency. Further, as described above, since there is a large difference in the relative magnetic permeability between the first core 20 and the second core 30, the transformer 10 includes a conventional bandpass filter having a narrow gap, Equivalent functions can be provided.

  Furthermore, since the transformer 10 includes the second core 20 having a low relative magnetic permeability, it can be brought close to the temperature characteristics of the conventional example in which the narrow gap exists and the conventional example in which the tape gap exists.

(Second Embodiment)
Hereinafter, a transformer 11 as a magnetic element according to a second embodiment of the present invention will be described with reference to FIG. In the present embodiment, the same components as those in the first embodiment will be described with the same reference numerals.

  Transformer 11 in the present embodiment is a so-called EE type transformer, first core 200 having a planar shape of E type, second core 300 having a planar shape of E type, coil bobbin 400, It has. Of these, the first core 200 and the second core 300 have substantially the same shape. Further, the materials of the first core 200 and the second core 300 are the same as those in the first embodiment described above, and the relative magnetic permeability of the first core 200 and the second core 300 is also as follows. This is the same as that in the first embodiment described above.

  Also in the present embodiment, the first core 200 is made of Mn-based ferrite (Hiμ (high mu) material) having a relative magnetic permeability of about 10,000. In addition, the material of the second core 300 is provided with a lower relative permeability than the material of the first core 200. Here, the relative permeability of the first core 200 is preferably provided in the range of 4 to 100 times the relative permeability of the second core 300. The relative permeability of the material of the second core 300 may be in the range of about 20 to about 2000. A more preferable range of the relative magnetic permeability is about 20 to about 1000.

  From the experimental results shown in FIGS. 5 to 7 and the like, when the relative permeability of the first core 200 is 10,000, and the relative permeability range of the second core 300 is 100 to 850, it is conventional. The same characteristics as those of the transformer can be obtained. An example of the material of the second core 300 having a low relative magnetic permeability is Ni-based ferrite.

  Moreover, the relative magnetic permeability with which the 1st core 200 is provided is not restricted to about 10,000, but should just exist in the range of 2000-30000. However, it is preferable that the relative permeability of the first core 200 is approximately 5000 or more (for example, when a material such as amorphous material is used), and the relative permeability of the first core 200 is approximately. If it is 10,000 or more, it becomes more preferable.

  Here, the recessed portions 210 and 310 of the first core 200 and the second core 300 in the present embodiment are more open compared to the recessed portion 21 in the first embodiment described above. Is provided. That is, the concave U-shaped recesses 21 and 31 in the first embodiment described above are open on the side of the mounted substrate plane among the side walls formed by the peripheral walls 24a and 24b and the upper walls 22 and 32, etc. It is provided in the state. On the other hand, the recessed portions 210 and 310 in the present embodiment are provided in a state where the upper walls 22 and 32 of the first embodiment described above are further opened.

  Therefore, the transformer 11 has a configuration in which a pair of peripheral walls 240 and 340 are disposed at both ends of each of the first core 200 and the second core 300 in the longitudinal direction (the arrow X direction in FIG. 8). (In FIG. 8, in order to distinguish the pair of peripheral walls 240 and the peripheral walls 340, the peripheral walls 240a and 240b and the peripheral walls 340a and 340b are used.) Also in this embodiment, the recessed portions 210 and 310 are provided with the column base 260 (corresponding to the first column base) and the column base 360 (corresponding to the second column base), respectively. Yes. In the present embodiment, the column base portions 260 and 360 are provided in a rectangular column shape that is long in the longitudinal direction of the first core 200 and the second core 300. Therefore, the through-hole 440 of the coil bobbin 400 is also a substantially rectangular hole corresponding to the shape of the column bases 260 and 360. Further, the column base portions 260 and 360 protrude in a state of being substantially parallel to the substrate to be mounted.

  In the present embodiment, a portion corresponding to the side bottom wall 23 of the first core 20 of the first embodiment is defined as the side bottom wall 230. Similarly, a portion corresponding to the side bottom wall 33 of the second core 30 is referred to as a side bottom wall 330.

  Also in the present embodiment, the protruding heights of the column base portions 260 and 360 are substantially the same height positions as the facing surface 250 of the first core 200 and the facing surface 350 of the second core 300. ing. Therefore, even when the first core 200 and the second core 300 are abutted, a gap is not formed between the column base 260 and the column base 360.

  Moreover, unlike the coil bobbin 40 in the first embodiment described above, the coil bobbin 400 of the present embodiment has three flanges unlike the configuration having a pair of flanges 42. Therefore, the coil bobbin 400 is not configured to have one winding part 41 like the coil bobbin 40, but has two winding parts.

  In the following description, the three collars in FIG. 8 are sequentially referred to as an upper collar part 421, a middle collar part 422, and a lower collar part 423 from the first core 200 toward the second core 300. . In addition, the two winding portions are also sequentially partitioned from the first core 200 toward the second core 300 by the first winding portion 411 (this portion is divided by the upper collar portion 421 and the middle collar portion 422. Portion), a second winding portion 412 (this portion is a portion partitioned by the middle collar portion 422 and the lower collar portion 423).

  The coil bobbin 400 of the present embodiment also includes a first terminal block 430 and a second terminal block 431. Here, from the first terminal block 430 and the second terminal block 431, a plurality of pin terminals 450 (five each from the first terminal block 430 and the second terminal block 431 in this embodiment) are provided. However, it protrudes downward. The pin terminal 450 is a part that is inserted into a hole provided in a mounting part of the substrate. Further, the terminal of the primary winding 50 or the secondary winding 60 is wound around the pin terminal 450, respectively. Therefore, the pin terminal 450 in the present embodiment serves as the binding terminal 45 and the mounting terminal 46 in the first embodiment described above.

  The first terminal block 430 and the second terminal block 431 are provided with a plurality of protrusions 460 that protrude downward from the lower surface thereof. The protrusion 460 has a length dimension shorter than that of the pin terminal 450. Therefore, when mounting on the substrate, the lower surface of the protrusion 460 contacts the substrate with the pin terminal 450 inserted in the hole. As a result, the pin terminal 450 is not inserted into the hole as far as the root, and the portion of the pin terminal 450 where the end of the primary winding 50 or the secondary winding 60 is entangled interferes with the substrate. It becomes possible to prevent. That is, in the pin terminal 450, a part for binding the terminal of the primary winding 50 or the secondary winding 60 is secured.

  Note that the pin terminal 450 may be configured to have only the role of the mounting terminal 46 in the first embodiment described above, and to separately provide a binding terminal corresponding to the binding terminal 45. good.

  When assembling the transformer 11 having such parts, the primary winding 50 and the secondary winding 60 are wound around the first winding portion 411 and the second winding portion 412, respectively. Further, the terminals of the primary windings 50 and 60 are respectively tangled with any one of the pin terminals 450. Then, the column base portions 260 and 360 are inserted into the through holes 440. When the first core 200 and the second core 300 are brought into contact with each other (contacted), the facing surfaces 250 and 350 of the peripheral walls 240 and 340 come into contact with each other and the facing surfaces 250 of the column base portions 260 and 360 are in contact with each other. 350 are also in contact with each other. Thereby, a narrow gap is not generated between the column base 260 and the column base 360. At this time, the first core 200 and the second core 300 are in contact with each other in the absence of a magnetic gap (narrow gap), and a closed magnetic path is formed by the contact.

  After such a butting, the first core 200 and the second core 300 are joined via, for example, an adhesive or a pressing member (not shown). The transformer 11 is assembled as described above.

  Also in the transformer 11 having such a configuration, it is possible to produce the same effects as the transformer 10 of the first embodiment described above. That is, even if no gap is provided between the first core 200 and the second core 300, the entire transformer 11 can obtain characteristics (desired characteristics) equivalent to those of a conventional transformer having a narrow gap. It becomes possible. Further, the presence of the second core 300 having a low relative magnetic permeability makes it possible to match the effective magnetic permeability and assist in the attenuation of the low frequency signal.

  Further, in the transformer 11, the primary winding 50 and the secondary winding 60 wound around the coil bobbin 400 are clearly partitioned by the intermediate flange portion 422. Therefore, the primary winding 50 and the secondary winding 60 can be easily wound, and the workability when the transformer 11 is assembled can be improved.

  Although the first and second embodiments of the present invention have been described above, the present invention can be variously modified in addition to this. This will be described below.

  In the first embodiment described above, the case where the first core 20 and the second core 30 forming the EP core are used as the transformer 10 has been described. In the above-described second embodiment, the case where the first core 200 and the second core 300 that form the EE core are used as the transformer 11 is described. However, the transformers 10 and 11 are not limited to using an EP core. For example, the present invention may be applied by using various signal cores such as an EI core, an EF core, an ER core, and an RM core as the first core and the second core.

  In the above-described first embodiment, the columnar column base 26 is the first column base, and the columnar column 36 is the second column base. Further, in the second embodiment described above, the quadrangular columnar column base 260 is used as the first column base, and the quadrangular columnar column base 360 is also used as the second column base. However, the first column base and the second column base may not be cylindrical or quadrangular, and can be variously changed, for example, an elliptical column or a triangular column.

  Further, in each of the above-described embodiments, the case where the present invention is applied to a magnetic element related to a winding coil that winds a conducting wire is described. However, the magnetic element is not limited to a winding coil, and the present invention may be applied to a printing type laminated coil and a thin film coil using vapor deposition / sputtering.

  Further, the magnetic element is not limited to the transformer constituted by the two windings 50 and 60, and the present invention may be applied to a transformer having three or more windings. For example, it may be configured to have one primary winding and two secondary windings.

  In the above-described embodiment, the first core 20 and the second core 30 are described as having symmetrical shapes. However, the first core 20 and the second core 30 may be asymmetric with respect to each other. Moreover, when the 1st core 20 and the 2nd core 30 make symmetrical shape, the structure provided with the identifier which can identify the 1st core 20 and the 2nd core 30 easily visually or tactilely is employ | adopted. May be.

  Furthermore, in the transformer 10, the frequency of the signal passed as a band pass filter is not limited to 13 kHz. As long as there is a difference in relative permeability between the first core 20 and the second core 30 as described above, any frequency band around a frequency higher than 13 kHz or near a frequency lower than 13 kHz is used. It may be allowed to pass through.

  In each of the above embodiments, a magnetic element such as a transformer having two windings (primary winding 50 and secondary winding 60) is described. A magnetic element using three or more windings is also described in the above modification. However, the magnetic element is not limited to a configuration having two or more windings, and a magnetic element having only one winding may be used. In this case, the magnetic element can function as various inductors, filters, and the like.

  The magnetic element of the present invention can be used in the field of electrical equipment.

1 is a perspective view showing a configuration of a transformer according to a first embodiment of the present invention. It is a disassembled perspective view which shows the structure of the transformer of FIG. It is a sectional side view which shows the structure of the transformer of FIG. It is a front view which shows the shape of the 1st core of the transformer of FIG. 1, or a 2nd core. It is a figure which shows the experimental result of the characteristic of the transformer | transformer of FIG. In the broken line, the characteristic of the transformer in which the relative permeability of the first core is 10,000 and the relative permeability of the second core is 100 is indicated by a solid line. It is a figure which shows the experimental result of the characteristic of the transformer | transformer of FIG. In the broken line, the characteristic of the transformer in which the relative permeability of the first core is 10,000 and the relative permeability of the second core is 400 is indicated by a solid line. It is a figure which shows the experimental result of the characteristic of the transformer | transformer of FIG. In the broken line, the characteristic of the transformer in which the relative permeability of the first core is 10,000 and the relative permeability of the second core is 850 is indicated by a solid line. It is a disassembled perspective view which shows the structure of the trans | transformer which concerns on the 2nd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10,11 ... Transformer 20,200 ... 1st core 21,210 ... Recessed fitting part 22 ... Upper wall (a part of 1st surrounding wall part)
23 ... Side bottom wall (part of the first peripheral wall)
24a, 24b ... peripheral wall (a part of the first peripheral wall)
25, 250 ... opposing surface 26, 260 ... column base (corresponding to the first column base)
30, 300 ... second core 31, 310 ... recessed fitting part 32 ... upper wall (part of second peripheral wall part)
33 ... Side bottom wall (part of the second peripheral wall)
34a, 34b ... peripheral wall (a part of the second peripheral wall)
35, 350 ... opposing surface 36, 360 ... column base (corresponding to the second column base)
50 ... Primary winding (corresponding to the first coil)
60 ... Secondary winding (corresponding to the second coil)
70 ... Circuit board 240, 340 ... Perimeter wall

Claims (8)

A first core;
A second core in contact with the first core;
A coil that receives a signal and is wound around at least one of the first core and the second core;
With
The relative permeability of the first core is higher than the relative permeability of the second core, and no magnetic gap exists between the first core and the second core. A closed magnetic circuit is formed in the state,
The magnetic element characterized by the above-mentioned. A first coil to which a signal is input;
A second coil to which a signal input to the first coil is transmitted;
A first core having a first column base around which the first coil is wound and a first peripheral wall disposed around the first column base;
A second core having a second column base around which the second coil is wound and a second peripheral wall disposed around the second column base;
Comprising
The relative permeability of the first core is provided higher than the relative permeability of the second core, and
The first column base and the second column base are in contact, and the first peripheral wall and the second peripheral wall are in contact,
The magnetic element characterized by the above-mentioned.   3. The magnetic element according to claim 1, wherein a relative permeability of the first core is provided in a range of 4 to 100 times with respect to a relative permeability of the second core. .   The relative permeability of the first core is in the range of 2000 to 30000, and the relative permeability of the second core is in the range of 20 to 2000. The magnetic element according to any one of the above.   5. The first core according to claim 1, wherein the first core is made of a Mn-based magnetic member, and the second core is made of a Ni-based magnetic member. The magnetic element described.   6. The magnetism according to claim 1, wherein the first core and the second core have a symmetrical shape with respect to a portion in contact with each other. 6. element.   The magnetic element according to claim 1, wherein the first core and the second core form an EP core.   Of the frequency of the signal transmitted from the first coil to the second coil due to the difference in relative permeability between the first core and the second core, the frequency deviates from a specific band. 3. The magnetic element according to claim 2, wherein the magnetic element functions as a band-pass filter that attenuates the amplitude of the signal below a threshold value.

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