JP6426370B2 - Electromagnetic induction - Google Patents

Description

  The present invention relates to an electromagnetic inductor such as a choke coil and a choke transformer that includes an inductor and is used in a smoothing circuit of a power supply circuit or the like.

  Conventionally, in order to obtain a stable direct current signal and to obtain a signal from which components higher than a predetermined frequency have been removed, an electromagnetic inductor is used. The electromagnetic inductor includes, for example, a cylindrical bobbin, a coil wound around the bobbin, and a magnetic core disposed in a magnetic circuit formed by energization of the coil. As the magnetic core, cores known as, for example, E-shaped, I-shaped and U-shaped cores are known from the external shape thereof. Further, as the magnetic core, for example, a ferrite core made of polycrystalline magnetic ceramic and a so-called dust core (hereinafter also referred to as dust core) are known. The dust core is also referred to as a dust core, and is, for example, a magnetic core which is made as a fine powder, covering a powder surface with an insulating film, compressed and solidified (pressure molding or the like).

  As a parameter of such a magnetic core, an AL value (also called an inductance coefficient) which is a value obtained by dividing an inductance value of a coil using the magnetic core by a value of the square of the number of turns of the coil is known. The AL value can be calculated theoretically from the permeability, the cross-sectional area of the magnetic core, the magnetic path length and the like, and a low AL value indicates, for example, that the effective permeability is low. In the dust core, the AL value tends to be low due to the presence of the insulating film. Therefore, to increase the inductance value of the dust core, for example, measures have been taken to increase the size of the magnetic core.

  However, in order to change the size of the magnetic core, it is necessary to remake the magnetic core, and it has been difficult to manufacture a magnetic core with a finely adjusted inductance value. Furthermore, in order to obtain a desired inductance value, the magnetic core has to be reworked each time, which requires complicated work such as reworking of the mold and also time for reworking. Therefore, as disclosed in Patent Document 1, the coil inner portion in the magnetic core is configured of a plurality of core pieces made of magnetic material, and the number of core pieces is changed to adjust the inductance value of the magnetic core. The reactor which made it possible is known.

JP 2012-84773 A

  However, in the above-mentioned prior art, in order to adjust the inductance value of the magnetic core, it is necessary to disassemble and change the number of core pieces, and the operation is complicated. Furthermore, in order to change the number of core pieces inside the coil, it is necessary to take out the magnetic core from the coil, which further complicates the operation.

  Then, an object of the present invention is to provide an electromagnetic induction machine in which adjustment of an inductance value becomes easy.

  As a result of various studies, the present inventor has found that the above object can be achieved by the present invention described below.

  That is, an electromagnetic induction device according to the present invention comprises a coil, a core body of a dust core system disposed in a magnetic circuit formed by energization of the coil, and a portion of the magnetic circuit disposed outside the core body. And an additional core to form the

  According to this configuration, the additional core is disposed outside the core body, so when adjusting the inductance value, the size of the core body is changed or the core body is disassembled to constitute the core body. Since it is not necessary to change the number of core pieces, adjustment of the inductance value becomes easy. Placing the additional core outside the core body means that the core body and the additional core are separate.

  In the present invention, preferably, the additional core is disposed at at least one end of the both ends of the core main body in the axial direction of the coil. The core body has a core piece which is E-shaped or U-shaped in a front view, and the additional core has a longitudinal direction parallel to the axial center direction of the coil and is formed on the E-shaped core piece. It may be arranged on the outer surface of the outer leg included or the outer surface of the U-shaped core piece. Furthermore, the core body has a core piece that is E-shaped or U-shaped in a front view, and the additional core has a longitudinal direction perpendicular to the axial direction of the coil, and the core of the E-shaped core The front and rear surfaces of the outer leg in the front view or the front and rear surfaces of the U-shaped core piece may be arranged.

  According to each above-mentioned composition, an additional core can be arranged in various forms on the outer side of the core body of each shape to installation space of an electromagnetic induction machine.

  The additional core is preferably in the form of an I, E or U shape. The additional core is preferably a ferrite core. By these, the additional core can be obtained inexpensively.

  Furthermore, the additional core is preferably disposed outside the coil. According to this configuration, the additional core is disposed outside the coil, and there is no need to take out the core body from the coil, so adjustment of the inductance value of the electromagnetic inductor becomes easy.

  The electromagnetic inductor according to the present invention facilitates adjustment of the inductance value.

It is a front view showing an electromagnetic induction machine concerning a 1st embodiment, (a) shows the state before an assembly, and (b) shows the state after an assembly. (A) is a front view showing the state after assembling about the modification of the electromagnetic induction machine concerning a 1st embodiment. (B) is a front view showing the state after assembling about another modification of the electromagnetic induction machine concerning a 1st embodiment. It is a front view showing an electromagnetic induction machine concerning a 2nd embodiment, (a) shows a state before assembling, (b) shows a state after assembling, (c) shows a state after assembling about a modification. (D) shows the state after assembly about another modification. (A) is a top view which shows the state before the assembly of the electromagnetic induction concerning 3rd Embodiment, (b) is a front view which shows the state before an assembly. (C) is a top view which shows the state after the assembly of the electromagnetic induction concerning 3rd Embodiment, (d) is a front view which shows the state after an assembly. It is a table showing the measurement result of the inductance value in the electromagnetic induction machine concerning a 1st-3rd embodiment.

  Hereinafter, embodiments of the present invention will be described based on the drawings. In the drawings, the same reference numerals indicate the same or corresponding portions, and the description thereof will be appropriately omitted unless there is a description such as a special change.

First Embodiment
FIG. 1 shows a front view and a plan view of the electromagnetic induction device 100 according to the first embodiment. The electromagnetic inductor 100 includes components of the bobbin 1, the coil 2, the terminal block 3, the core body 4, and the additional core 5. FIG. 1 (a) is a front view before these components are assembled, and FIG. 1 (b) is a front view after the components are assembled. FIG. 1 (c) is a plan view after being assembled. The bobbin 1 is a hollow cylinder molded of resin or the like, and has an insertion hole 11 along the axial center C of the cylinder inside. The bobbin 1 is, for example, a cylinder. In this case, the axial center C substantially coincides with the axial center of the coil described later. The coil 2 is wound around the bobbin 1 and generates a magnetic field by being energized from a power supply (not shown). The terminal block 3 is integrally formed on the bobbin 1 and a terminal connected to a coil is disposed. The terminal block 3 may be separate from the bobbin 1. Further, the outer diameter of the coil 2 is set equal to or smaller than the outer diameter of the substantially disc-like flange portion 1a which is the end opposite to the terminal block 3 in the bobbin 1 and the coil 2 is It does not project radially outward from the bobbin 1.

  The core body 4 is a magnetic core including a ferromagnetic material disposed in a magnetic circuit formed by energization of the coil 2. The core body 4 is, for example, a so-called EE type, and an intermediate leg is inserted in the insertion hole 11 inside the bobbin 1. When the core body 4 is, for example, a so-called UU type, one leg of the core body 4 is inserted into the insertion hole 11 inside the bobbin 1 and the other leg is located outside the coil 2. The core body 4 is configured by a pair of a first core piece 41 and a second core piece 42 which are E-shaped in a front view in which the shape can be visually recognized. The first and second core pieces 41 and 42 are dust-based cores which are made by making the ferromagnetic material into fine powder, covering the surface of the powder with an insulating film, and compressing and solidifying the powder. The core main body 4 may have a shape of EI, EU, UI, II or the like, and is not limited to a pair. The first core piece 41 has two outer legs 411, middle legs 412, and a connecting portion 413 connecting them, and the second core piece 42 has two outer legs 421, middle legs 422, and these And a connecting portion 423 connecting the two. The first core piece 41 and the second core piece 42 form an integral core body 4 with outer legs and middle legs facing each other. The outer legs 411 and 421 have a rectangular cross section, and the middle legs 412 and 422 have a circular cross section, but the shape of the cross section is not limited thereto. Here, the dimensions of the core body 4 are, for example, about 42 mm × 35 mm × 11 mm in longitudinal L × horizontal W × depth D in a front view, and the lateral dimensions of the middle leg and the outer leg are, for example, about 11 mm and about respectively. It is 5 mm.

  The additional core 5 is a magnetic core, and is attached to the outside of the core main body 4 by being taped and fixed or pasted with a varnish or the like. Here, a pair of additional cores 5, 5 are disposed outside the core body 4 by the above fixing or pasting to form a part of the magnetic circuit. The additional core 5 is an I-shaped core. The I-shaped core is flat and substantially rectangular. The additional core 5 may be disposed at at least one of the two ends of the core body 4 in the axial direction of the coil, but in the present embodiment, the additional core 5 is disposed at both ends of the core body 4 . Specifically, the pair of additional cores 5 and 5 are the E-shaped first core piece 41 and the E-shaped second core piece 42, respectively, on the opposite side of the middle leg 412 and the two outer legs 411 in the connecting portions 413 and 423 Is affixed to the back surface 413a, 423a. The additional core 5 is, for example, a ferrite core or a dust core, but is a ferrite core in the present embodiment. The additional core 5 may be a dust core, and is not limited to a pair. Here, as the dimensions of the additional core 5 which is an I-shaped core, as shown in FIGS. 1B and 1C, the thickness T1 × horizontal W1 × depth D1 is, for example, about 6 mm × 35 mm × 11 mm.

  In the assembled state shown in FIG. 1B, the middle legs 412 and 422 of the core main body 4 are inserted into the insertion holes 11 in the bobbin 1 from the state before the constituent members shown in FIG. 1A are assembled. The outer legs and the middle legs are opposed to each other, and a pair of additional cores 5 are attached to both the back surfaces 413a and 423a of the core body 4 to achieve the above.

  The additional core 5 may have, for example, an E shape, a U shape, or the like in addition to the I-shaped core. FIG. 2A shows an electromagnetic inductor 100A which is a modification of the case of using the pair of E-shaped additional cores 5A and 5A in a front view. Moreover, the electromagnetic induction machine 100B which is another modification at the time of using a pair of U-shaped additional cores 5B and 5B is shown in FIG.2 (b).

  According to the present embodiment, the additional cores 5, 5A, 5B are disposed outside the core body 4 by the engagement or sticking, etc. to form a part of the magnetic circuit, so the additional cores 5, 5A, 5B are By being attached to the core body 4, the shape and size of the magnetic circuit change, and the inductance of the coil 2, that is, the inductance of the electromagnetic inductors 100, 100A, 100B changes. Therefore, the electromagnetic inductors 100, 100A, 100B include the additional cores 5, 5A, 5B disposed outside the core body 4, thereby changing the size of the core body 4 when adjusting the inductance value. Since it is not necessary to disassemble the core body 4 to change the number of core pieces constituting the core body 4, adjustment of the inductance value becomes easy. Furthermore, fine adjustment of the inductance of the electromagnetic inductor becomes possible by adjusting the number, material, shape, size, etc. of the additional cores to be attached. Further, since the additional cores 5, 5A and 5B are disposed outside the coil 2 and there is no need to take out the core main body 4 from the coil 2, adjustment of the inductance value is further facilitated.

Second Embodiment
Next, a second embodiment will be described.

  FIG. 3 shows a front view of the electromagnetic inductors 100C, 100D, 100E according to the second embodiment. The drive devices 100C, 100D, and 100E according to the present embodiment include, for example, the respective constituent members of the bobbin 1, the coil 2, the terminal block 3, the core body 4, and the additional cores 5C, 5D, and 5E, as in the first embodiment. Prepare. FIG. 3 (a) shows the state before these components are assembled, FIG. 3 (b) shows the state after assembly, and FIG. 3 (c) shows the state after assembly for the modification. 3 (d) shows the state after assembly about another modification.

  In the first embodiment, the pair of additional cores 5, 5, 5A, 5A, 5B, 5B are disposed at the both end portions of the core main body 4, but in the present embodiment, the core main body 4 is viewed in the front view Unlike the first embodiment, the additional cores 5C, 5D, and 5E have core pieces that have an E shape, and the longitudinal direction is parallel to the axial center direction of the coil 2, and the E core pieces 41, 42 is disposed on the outer surface of the outer leg included. That is, the additional cores 5C, 5D, 5E are disposed in a plane parallel to the axis C of the outer leg. Also in the present embodiment, the core body 4 is EE-shaped, and has a pair of E-shaped first core pieces 41 and second core pieces 42. In the present embodiment, the additional cores 5C, 5D, and 5E are disposed on both of the first outer leg 411 and the second outer leg 413, but may be one of the outer legs. Here, when the core body 4 has a core piece which is U-shaped in the front view, the additional cores 5C, 5D, 5E are disposed on the outer side surfaces of the U-shaped core pieces 41, 42. That is, also in this case, the additional cores 5C, 5D, 5E are disposed in a plane parallel to the axial center C of the coil in the outer leg.

  Also in the present embodiment, the additional cores 5C, 5D, 5E may be I-shaped, E-shaped or U-shaped. FIGS. 3A and 3B show an electromagnetic inductor 100C using a pair of I-shaped additional cores 5C and 5C. Moreover, what is shown by FIG.3 (c) is electromagnetic inductor 100D which is a modification using a pair of U-shaped additional cores 5D and 5D. Moreover, what is shown by FIG.3 (d) is the electromagnetic inductor 100E which is another modification using a pair of E-shaped additional cores 5E and 5E. Here, the dimension of the additional core 5C which is I-shaped is, for example, about 21 mm × 5 mm × 11 mm in length L2 × thickness T2 × depth D2 (not shown) in FIG. The external dimensions of a certain additional core 5D or 5E are, for example, about 35 mm × 21 mm × 11 mm in length L2 × thickness T2 × depth D2 (not shown) in FIGS. 3 (c) and (d). Note that only one additional core of the pair of additional cores may be used.

  The present embodiment is different from the first embodiment only in the arrangement of the additional cores as described above, and the other points are the same as the first embodiment. Therefore, the other description is omitted.

  Also in the present embodiment, as in the first embodiment, the inductances of the electromagnetic inductors 100C, 100D, and 100E can be easily adjusted, and fine adjustment of the inductances can also be performed. Furthermore, as compared with the first embodiment, the configuration of the present embodiment is effective when applied, for example, when the dimension in the height direction (the axial direction) of the electromagnetic induction device is restricted. is there.

Third Embodiment
Next, a third embodiment will be described.

  FIG. 4 shows an electromagnetic inductor 100F according to the third embodiment. The drive device 100F of the present embodiment includes, for example, the respective components of the bobbin 1, the coil 2, the terminal block 3, the core body 4, and the additional core, as in the first embodiment. FIG. 4 (a) shows a plan view of the state before these components are assembled, and FIG. 4 (b) shows a front view of the same state. FIG. 4 (c) shows a plan view of the assembled state, and FIG. 4 (d) shows a front view of the same state.

  In the present embodiment, the core body 4 has a core piece which is E-shaped in a front view, and the additional core 5F is different from the first embodiment in that the longitudinal direction is perpendicular to the axial center C of the coil 2 The front and rear surfaces 4a and 4b of the outer legs of the E-shaped core pieces 41 and 42 with respect to the front view, that is, planes disposed orthogonal to the front view direction. Thus, the additional core 5F is disposed in a plane perpendicular to the axial center C in the outer leg. Also in the present embodiment, the core main body 4 is an EE type, and includes the pair of first core pieces 41 and the second core pieces 42. Although the additional core 5F is disposed on the front and rear surfaces 4a and 4b of the pair of outer legs 411 and 411 in this embodiment, the additional core 5F may be disposed on either the front surface 4a or the rear surface 4b of the outer legs. . Here, when the core body 4 has a core piece which is U-shaped in a front view, the additional core 5F is disposed on the front and rear surfaces 4a, 4b of the U-shaped core pieces 41, 42 in front view. . That is, also in this case, the additional core 5F is disposed in a plane perpendicular to the axial center C of the outer leg.

  Although the shape of the additional core 5F is U-shaped, it may be I-shaped or E-shaped also in this embodiment. Here, the pair of leg portions 5Fa and 5Fa of the pair of additional cores 5F and 5F which are U-shaped cores respectively contact the front and rear surfaces 4a and 4b of the outer leg 411 of the EE-shaped core main body 4 and the pair of leg portions Connecting portions 5Fb, 5Fb connecting the 5Fa, 5Fa are respectively close to the outer peripheral surface of the coil 2. Therefore, the dimension P which each protrudes in the front-back direction from the said collar part 1a of the bobbin 1 shown in FIG.4 (d) can be made small. Here, the external dimensions of the additional core 5F are, for example, about 11 mm × 35 mm × 21 mm in thickness T3 × lateral L3 × depth D3.

  The present embodiment is different from the first embodiment only in the arrangement of the additional cores as described above, and the other points are the same as the first embodiment. Therefore, the other description is omitted.

  Also in the present embodiment, as in the first embodiment, the inductance of the electromagnetic inductor 100F can be easily adjusted, and fine adjustment of the inductance can also be performed. Furthermore, compared to the first and second embodiments, in the configuration of the present embodiment, when the additional core fits in the space surrounded by the bobbin, the coil and the terminal block, that is, in the case of the dimension P = 0, electromagnetic induction The overall dimensions of the vessel do not change before and after the additional core is attached.

  The table | surface of the measurement result of the inductance value (L [micro | micron | mu H]) in the electromagnetic induction machine of the above 1st Embodiment-3rd Embodiment is shown in FIG. The conditions of the voltage applied to the coil and the frequency are described in [] of the lower four rows of the leftmost column in the table. Column A shows the inductance value of the electromagnetic inductor when no additional core is attached. Column B shows the inductance value in the case of the electromagnetic inductor shown in FIG. 1, and columns C and D show the inductance values in the case of the electromagnetic inductor shown in FIGS. First embodiment). Rows E, F, and G show inductance values in the case of the electromagnetic inductor shown in FIGS. 3 (a) and (b), (c), and (d), respectively (second embodiment). Column H shows the inductance value in the case of the electromagnetic inductor shown in FIG. 4 (third embodiment). Note that columns I and J show inductance values in the case of an electromagnetic inductor in which the additional core 5 (FIG. 1) is a dust core in the first embodiment. The additional core 5 of the row J has the same AL value as the dust core of the main body core 4, and the additional core 5 of the row I is set to have a higher AL value than the dust core of the main body core 4. In the measurement results shown in rows B to J, the inductance value is increased by 10 to 70 μH with respect to the measurement results shown in row A, and the additional core is disposed outside the core body as in the above embodiments. Thus, it can be understood that fine adjustment of the inductance value is possible.

  The present invention is not limited to the above embodiments, and various additions, modifications, or deletions can be made without departing from the scope of the present invention. Therefore, such is also included in the scope of the present invention.

2 coil 4 core body 41, 42 core piece 411, 413 outer leg 5, 5A to 5F additional core 100, 100A to 100F electromagnetic inductor C axial center

Claims (7)

A coil, a core body of a dust-based core disposed in a magnetic circuit formed by energizing the coil, and an additional core disposed outside the core body and forming a part of the magnetic circuit ;
The core body has at least two legs, and the coil is disposed around an intermediate leg which is one leg, and an outer leg which is the other leg is disposed outside the coil, and A connecting part connecting the middle leg and the outer leg,
The additional core is disposed outside the core body and at the coupling portion . In claim 1,
The additional core is an electromagnetic induction device disposed at at least one end of at least one of both ends of the core main body in the axial direction of the coil and at the connection portion . A coil, a core body of a dust-based core disposed in a magnetic circuit formed by energizing the coil, and an additional core disposed outside the core body and forming a part of the magnetic circuit;
The core body has a core piece which is E-shaped or U-shaped in a front view, and the additional core is included in the E-shaped core piece with the longitudinal direction parallel to the axial direction of the coil. An electromagnetic inductor disposed on the outer surface of the outer leg or the outer surface of the U-shaped core piece. A coil, a core body of a dust-based core disposed in a magnetic circuit formed by energizing the coil, and an additional core disposed outside the core body and forming a part of the magnetic circuit;
The core body has a core piece which is E-shaped or U-shaped in a front view, and the additional core has a longitudinal direction perpendicular to the axial direction of the coil, and the outer leg of the E-shaped core piece An electromagnetic inductor disposed on the front and rear surfaces of the front view or the front and rear surfaces of the U-shaped core piece. In any one of claims 1 to 4,
An electromagnetic inductor wherein the additional core is in the form of an I, E or U shape. In any one of claims 1 to 5,
The additional core is a ferrite core. In any one of claims 1 to 6,
The additional core is an electromagnetic inductor disposed outside the coil.

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