JP2016171192A - Induction apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an induction apparatus in which the leakage flux interlinking with a coil can be reduced, and manufacture of which can be facilitated while reducing the number of components.SOLUTION: A third inner surface 53a is arranged at a position closer to the axis line of a first leg 21b and a second leg 22b than a first inner surface 51a and a second inner surface 52a. Consequently, positional deviation of a coil element 31 in a third core 23 to a direction perpendicular to the winding center axis line L of the coil element 31 is suppressed. Furthermore, a first core 21 and a first bottom face 51e come into contact, and a cavity 54 is formed, as a first gap G1, between the end face 21e of the first leg 21b and the third core 23. Consequently, it is not required to interpose a gap plate between the end face 21e of the first leg 21b and the third core 23, for forming the first gap G1. Furthermore, the first gap G1 and a second gap G2 are formed, without molding a bobbin 40 while embedding the third core 23, like prior art.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an induction device having a magnetic core and a coil wound around the magnetic core.

  An induction device such as a reactor or a transformer has a magnetic core and a coil wound around the magnetic core. In general, the current flowing through the coil wound around the magnetic core increases, and the magnetic flux generated by the current flowing through the coil is determined by the type of magnetic material forming the magnetic core and the shape and size of the magnetic core. If the amount exceeds this value, the magnetic core is magnetically saturated, and the performance as a reactor or a transformer deteriorates. Therefore, by providing a gap in the magnetic flux path (magnetic path) of the magnetic core, the magnetic saturation of the magnetic core is suppressed.

  However, when a gap exists, leakage magnetic flux is generated around the gap from the magnetic core. When the coil is wound around the gap and the leakage magnetic flux is linked to the coil wound around the gap, an eddy current is generated in the coil due to the leakage magnetic flux linking the coil. As a result, the performance as a reactor or a transformer deteriorates.

  Therefore, as shown in FIG. 6, the magnetic flux M100 in the leg portions of the first core 101 and the second core 102 is chained between the end surface of the leg portion of the first core 101 and the end surface of the leg portion of the second core 102. A third core 103 having a smaller cross-sectional area where the magnetic flux M100 is linked than the cross-sectional area is arranged. A first gap 104 is formed between the end surface of the leg portion of the first core 101 and the third core 103, and a second gap is formed between the end surface of the leg portion of the second core 102 and the third core 103. 105 is formed. According to this, the magnetic flux M <b> 100 that flows through the legs of the first core 101, the third core 103, and the second core 102 flows so as to converge at the third core 103. Therefore, even if the coil 106 is disposed around the first gap 104 and the second gap 105, leakage magnetic flux leaking toward the coil 106 is hardly generated around the first gap 104 and the second gap 105. As a result, the leakage magnetic flux linked to the coil 106 is reduced (for example, Patent Document 1).

Japanese Patent No. 2791817

  Incidentally, as shown in FIG. 6, the first core 101, the second core 102, the third core 103, and the coil 106 are arranged in a state in which insulation is ensured by a resin bobbin 110. In FIG. 6, in order to form the first gap 104, the first gap plate 111 is interposed between the end surface of the leg portion of the first core 101 and the third core 103, and the second gap 105 is formed. Therefore, the second gap plate 112 is interposed between the end surface of the leg portion of the second core 102 and the third core 103. Therefore, in order to form the first gap 104 and the second gap 105, the first gap plate 111 and the second gap plate 112 are required, which increases the number of parts and takes time for manufacturing. Furthermore, the positioning in the direction orthogonal to the winding center axis of the coil 106 in the third core 103 (the direction of the arrow X10) is not made, and the winding core axis of the coil 106 in the third core 103 is not aligned. As a result, the leakage flux generated around the first gap 104 and the second gap 105 may be linked to the coil 106 due to the displacement in the orthogonal direction.

  The present invention has been made in order to solve the above-described problems, and the object thereof is to reduce leakage magnetic flux interlinking with a coil and to facilitate manufacture while reducing the number of parts. It is in providing the induction device which can be.

  An induction device that solves the above problem includes a magnetic core that forms a magnetic path, a coil wound around the magnetic core, and a resin bobbin that insulates the magnetic core from the coil, The core includes a first core having a first leg, a second core having a second leg, and a third core disposed between an end surface of the first leg and an end surface of the second leg. And having a first gap between the end face of the first leg and the third core, and having a second gap between the end face of the second leg and the third core. The coil is wound around from the first leg portion to the second leg portion, and the area of the cross section where the magnetic flux in the third core is linked is the first leg portion and the second leg portion. Is an induction device that is smaller than the cross-sectional area where the magnetic flux is interlinked, wherein the bobbin is A first receiving recess in which at least a part of one leg is received; a second receiving recess in which at least a part of the second leg is received; and a first receiving recess that communicates with the first receiving recess. A third housing recess that houses at least a portion thereof, wherein the first housing recess has a first inner surface located in a direction orthogonal to the winding center axis of the coil, and the second housing The recess has a second inner surface positioned in a direction orthogonal to the winding center axis of the coil, and the third receiving recess is a first position positioned in a direction orthogonal to the winding center axis of the coil. And the third inner surface is disposed closer to the axis of the first leg and the second leg than the first inner surface and the second inner surface, and the first receiving recess The first bottom surface and the third inner surface are continuous, and the front of the bobbin The bottom wall having both the second bottom surface of the second housing recess and the third bottom surface of the third housing recess forms the second gap, and the first core and the first bottom surface are in contact with each other, A gap as the first gap is formed between the end face of the first leg and the third core.

  According to this, the position of the third inner surface of the third housing recess with respect to the axis of the first leg and the second leg is the same as the first inner surface of the first housing recess and the second inner surface of the second housing recess. Compared with the case where it arrange | positions, the position shift to the direction orthogonal to the winding center axis line of the coil in a 3rd core is suppressed. Therefore, the leakage flux generated around the first gap and the second gap is prevented from interlinking with the coil due to the positional deviation in the direction orthogonal to the winding center axis of the coil in the third core. be able to. In addition, since the first core and the first bottom surface are in contact with each other and a gap as the first gap is formed between the end surface of the first leg portion and the third core, in order to form the first gap, There is no need to interpose a gap plate between the end face of the first leg and the third core. Therefore, the leakage magnetic flux linked to the coil can be reduced, and the induction device can be easily manufactured while reducing the number of parts.

In the guide device, it is preferable that a contact portion that protrudes between the end surface of the first leg portion and the third core and contacts the third core is provided on the third inner surface.
According to this, since the movement from the 3rd accommodation recessed part in the 3rd core toward the 1st accommodation recessed part can be controlled when the 3rd core contacts the contact part, positioning accuracy in the 3rd core is improved. Can be improved.

In the induction device, it is preferable that an interposition part interposed between the first gap and the coil protrudes from an end surface of the first leg part.
According to this, since the leakage magnetic flux generated around the first gap is linked to the interposition part, the leakage magnetic flux generated around the first gap is hardly linked to the coil. Therefore, the leakage magnetic flux linked to the coil can be reduced.

  According to the present invention, it is possible to reduce the leakage magnetic flux interlinking with the coil and to facilitate the manufacture while reducing the number of parts.

Sectional drawing which shows the induction | guidance | derivation apparatus in 1st Embodiment. Sectional drawing which expands and shows a 3rd core periphery. Sectional drawing which decomposes | disassembles and shows a 1st core, a 2nd core, a 3rd core, a bobbin, and a coil. Sectional drawing which expands and shows the 3rd core periphery in 2nd Embodiment. Sectional drawing which expands and shows the 3rd core periphery in 3rd Embodiment. Sectional drawing which expands and shows the 3rd core periphery in the guidance apparatus of a prior art example.

(First embodiment)
Hereinafter, a first embodiment in which a guidance device is embodied will be described with reference to FIGS. In addition, the guidance apparatus of embodiment described below comprises the reactor apparatus which is a vehicle-mounted electronic device.

  As shown in FIG. 1, the induction device 11 includes a magnetic core 20 that forms a magnetic path, a coil 30 wound around the magnetic core 20, and a resin bobbin 40 that insulates the magnetic core 20 from the coil 30. It has. The magnetic core 20 has a first core 21 and a second core 22. The first core 21 and the second core 22 are U-shaped cores. The first core 21 and the second core 22 are magnetic bodies and are formed of a dust core.

  The first core 21 is formed of a flat plate portion 21a having a substantially rectangular flat plate shape, and a pair of columnar first leg portions 21b extending from both longitudinal ends of the flat plate portion 21a toward the second core 22. . The second core 22 is formed of a flat plate portion 22a having a substantially rectangular flat plate shape, and a pair of columnar second leg portions 22b extending from both ends in the longitudinal direction of the flat plate portion 22a toward the first core 21. . The first core 21 and the second core 22 have the same shape. The first core 21 and the second core 22 are configured such that the end surfaces 21e in the extending direction of the pair of first leg portions 21b and the end surfaces 22e in the extending direction of the pair of second leg portions 22b face each other. Has been placed.

  The coil 30 includes two coil elements 31 wound around the pair of first leg portions 21b and the pair of second leg portions 22b, respectively. Therefore, the coil 30 is wound around the first leg 21b and the second leg 22b from the first leg 21b to the second leg 22b. The coil elements 31 are adjacent to each other with the winding center axes L of the coil elements 31 arranged in parallel to each other. In the present embodiment, the axes of the first leg portion 21 b and the second leg portion 22 b coincide with the winding center axis L of each coil element 31. Each coil element 31 is formed by edgewise bending a single conductive plate. And each coil element 31 is connected by the connection part 34 provided in the space | gap 33 formed adjacent to each coil element 31. FIG. The winding direction of each coil element 31 is different.

  Furthermore, the magnetic core 20 includes a third core 23 disposed between the end surfaces 21e of the pair of first leg portions 21b and the end surfaces 22e of the pair of second leg portions 22b. The third core 23 is an I-type core (columnar shape). The third core 23 is a magnetic body and is formed of a dust core.

  As shown in FIG. 2, the area of the cross section where the magnetic flux M1 in the third core 23 is linked is smaller than the area of the cross section where the magnetic flux M1 is linked in the first leg portion 21b and the second leg portion 22b. . That is, the width H1 along the radial direction of the first leg portion 21b and the width H2 along the radial direction of the second leg portion 22b are larger than the width H3 along the radial direction of the third core 23. The width H1 of the first leg portion 21b and the width H2 of the second leg portion 22b are the same.

  As shown in FIG. 1, the bobbin 40 includes a pair of bobbin elements 40 a that insulate the coil elements 31 and the magnetic core 20 from each other. The bobbin element 40a is connected to the first tube portion 41 extending along the winding center axis L of the coil element 31, and the first tube portion 41 in the winding center axis L of the coil element 31 while continuing to the first tube portion 41. Has a second cylindrical portion 42 extending to the opposite side. An annular flange 43 that extends in a direction orthogonal to the winding center axis L of the coil element 31 protrudes from the outer surface on the distal end side of the second cylindrical portion 42. Each bobbin element 40 a is connected by a connecting portion 44 that connects each flange 43.

  As shown in FIG. 2, the 1st cylinder part 41 has the 1st accommodating recessed part 51 in which the 1st leg part 21b is accommodated. The 2nd cylinder part 42 has the 2nd accommodation recessed part 52 in which the 2nd leg part 22b is accommodated. The first tube portion 41 has a third housing recess 53 that communicates with the first housing recess 51 and that houses the third core 23. The first accommodating recess 51 has a first inner surface 51 a located in a direction orthogonal to the winding center axis L of the coil element 31. The second housing recess 52 has a second inner surface 52 a located in a direction orthogonal to the winding center axis L of the coil element 31. The third housing recess 53 has a third inner surface 53 a located in a direction orthogonal to the winding center axis L of the coil element 31.

  The third inner surface 53a is disposed closer to the axis of the first leg portion 21b and the second leg portion 22b (the winding center axis L of the coil element 31) than the first inner surface 51a and the second inner surface 52a. The width H4 of the third inner surface 53a is narrower than the width H1 of the first leg portion 21b and the width H2 of the second leg portion 22b. The first bottom surface 51e of the first housing recess 51 and the third inner surface 53a are continuous. The length D1 of the third inner surface 53a in the direction along the winding center axis L of the coil element 31 is longer than the length D2 of the third core 23 in the direction along the winding center axis L. ing.

  The end surface 21e of the first leg 21b and the first bottom surface 51e are in contact with each other, and a gap 54 is formed between the end surface 21e of the first leg 21b and the third core 23. The gap 54 functions as the first gap G1. The bottom wall 45 having both the second bottom surface 52e of the second housing recess 52 and the third bottom surface 53e of the third housing recess 53 in the bobbin 40 is between the end surface 22e of the second leg 22b and the third core 23. Has been placed. The bottom wall 45 functions as the second gap G2.

  The gap length L1 of the first gap G1 and the gap length L2 of the second gap G2 are the same length. The gap length L1 of the first gap G1 is the distance of the gap 54 between the end surface 21e of the first leg 21b and the third core 23. The gap length L2 of the second gap G2 is the thickness of the bottom wall 45.

  As shown in FIG. 3, as an assembly procedure of the guidance device 11, first, the bobbin 40 is arranged with respect to the second core 22 so that the pair of second leg portions 22 b are accommodated in the second accommodation recess 52. The Subsequently, the coil 30 is mounted on the bobbin 40 so that the pair of coil elements 31 are mounted on the flanges 43 and the connecting portion 34 of the coil 30 is mounted on the connecting portion 44 of the bobbin 40. Be placed. Subsequently, the first core 21 is disposed with respect to the bobbin 40 so that the third core 23 is accommodated in the third accommodating recess 53 and the pair of first leg portions 21 b is accommodated in the first accommodating recess 51. As a result, the guidance device 11 is assembled. In this case, the third core 23 is press-fitted and accommodated in the third accommodation recess 53.

Next, the operation of the first embodiment will be described.
As shown in FIG. 2, the area of the cross section where the magnetic flux M1 in the third core 23 is linked is smaller than the area of the cross section where the magnetic flux M1 is linked in the first leg portion 21b and the second leg portion 22b. Therefore, in the magnetic flux M1 flowing through the magnetic core 20, the magnetic flux M1 flowing through the first leg 21b, the third core 23, and the second leg 22b flows so as to converge at the third core 23. Therefore, even if the coil 30 is disposed around the first gap G1 and the second gap G2, a leakage magnetic flux that leaks toward the coil 30 is hardly generated around the first gap G1 and the second gap G2. As a result, the leakage magnetic flux linked to the coil 30 is reduced.

  The third inner surface 53a is disposed closer to the axis of the first leg portion 21b and the second leg portion 22b than the first inner surface 51a and the second inner surface 52a. Therefore, the third inner surface 53a is compared with the case where the positions of the first leg portion 21b and the second leg portion 22b with respect to the axis line are arranged at the same position as the first inner surface 51a and the second inner surface 52a. The positional deviation in the direction orthogonal to the winding center axis L of the coil element 31 is suppressed. As a result, the leakage flux generated around the first gap G1 and the second gap G2 due to the positional deviation in the direction perpendicular to the winding center axis L of the coil element 31 in the third core 23 is chained to the coil 30. Crossing is suppressed.

In the first embodiment, the following effects can be obtained.
(1) The third inner surface 53a is disposed at a position closer to the axis of the first leg portion 21b and the second leg portion 22b than the first inner surface 51a and the second inner surface 52a. According to this, as compared with the case where the third inner surface 53a is arranged at the same position as the first inner surface 51a and the second inner surface 52a with respect to the axis of the first leg portion 21b and the second leg portion 22b, The positional deviation in the direction orthogonal to the winding center axis L of the coil element 31 in the three cores 23 is suppressed. Therefore, the leakage flux generated around the first gap G1 and the second gap G2 due to the positional deviation in the direction perpendicular to the winding center axis L of the coil element 31 in the third core 23 is linked to the coil 30. Can be suppressed. In addition, the third core 23 is press-fitted and accommodated in the third accommodating recess 53, so that the first core 21 and the first bottom surface 51e come into contact with each other, and the end surface 21e of the first leg portion 21b, the third core 23, A gap 54 as the first gap G1 is formed between the two. For this reason, it is not necessary to interpose a gap plate between the end surface 21e of the first leg portion 21b and the third core 23 in order to form the first gap G1. Therefore, the leakage magnetic flux linked to the coil 30 can be reduced, and the induction device 11 can be easily manufactured while reducing the number of components.

  (2) The third inner surface 53a has a third core as compared with the case where the positions of the first leg portion 21b and the second leg portion 22b with respect to the axis are the same positions as the first inner surface 51a and the second inner surface 52a. 23 is prevented from shifting in a direction orthogonal to the winding center axis L of the coil element 31. According to this, the third bottom surface 53e of the third accommodating recess 53 and the third core 23 are suppressed in order to suppress the positional deviation in the direction orthogonal to the winding center axis L of the coil element 31 in the third core 23. There is no need to apply an adhesive between the two. Therefore, the adhesive application step can be eliminated, and the induction device 11 can be easily manufactured.

(Second Embodiment)
Hereinafter, a second embodiment in which the guidance device is embodied will be described with reference to FIG. In the embodiment described below, the same components as those in the first embodiment described above are denoted by the same reference numerals, and the redundant description thereof is omitted or simplified.

  As shown in FIG. 4, the third inner surface 53 a is provided with a pair of contact portions 46 that protrude between the end surface 21 e of the first leg portion 21 b and the third core 23 and contact the third core 23. ing. The end surface 46a on the third bottom surface 53e side of the third housing recess 53 in the contact portion 46 has a flat surface extending along a direction orthogonal to the third inner surface 53a. Further, the end surface 46b on the first housing recess 51 side of the contact portion 46 has a tapered surface shape that inclines toward the third bottom surface 53e as it goes inward from the third inner surface 53a. The third core 23 is housed in the third housing recess 53 while forcibly expanding the first tube portion 41 outward while being pressed against the end surface 46 b of each contact portion 46.

Next, the operation of the second embodiment will be described.
When the third core 23 abuts on the end surface 46 a of each abutment portion 46, the movement from the third accommodation recess 53 to the first accommodation recess 51 in the third core 23 is restricted.

Therefore, according to the second embodiment, in addition to the same effects as the effects (1) and (2) of the first embodiment, the following effects can be obtained.
(3) A pair of abutting portions 46 projecting between the end surface 21e of the first leg portion 21b and the third core 23 and contacting the third core 23 are provided on the third inner surface 53a. According to this, when the 3rd core 23 contact | abuts to the end surface 46a of each contact part 46, the movement toward the 1st accommodation recessed part 51 from the 3rd accommodation recessed part 53 in the 3rd core 23 can be controlled. Therefore, the positioning accuracy in the third core 23 can be improved.

(Third embodiment)
Hereinafter, a third embodiment in which the guidance device is embodied will be described with reference to FIG.
As shown in FIG. 5, an intervening portion 21 f interposed between the first gap G <b> 1 and the coil 30 protrudes around the entire outer edge of the end surface 21 e of the first leg portion 21 b. An intervening portion 22f interposed between the second gap G2 and the coil 30 protrudes from the entire outer edge of the end surface 22e of the second leg portion 22b. In the first core 21, the second core 22, and the third core 23, the distance L3 between the interposition portions 21f and 22f is larger than the sum of the gap length L1 of the first gap G1 and the gap length L2 of the second gap G2. It is arranged to be long.

  The interposition part 21f is an annular shape extending over the entire outer edge of the end face 21e of the first leg part 21b. The interposition part 22f is an annular shape extending over the entire outer edge of the end surface 22e of the second leg part 22b. The intervening portion 21f faces the entire outer edge of the third core 23 on the first core 21 side and covers the entire outer edge of the third core 23 on the first core 21 side. In addition, the interposition portion 22f faces the entire outer edge of the third core 23 on the second core 22 side and covers the entire outer edge of the third core 23 on the second core 22 side. An inner peripheral surface 21r of the intervening portion 21f is continuous with the end surface 21e of the first core 21 and is curved in an arc shape. The inner peripheral surface 22r of the interposition part 22f is continuous with the end surface 22e of the second core 22 and is curved in an arc shape.

  An insertion groove 52b into which the interposition part 22f is inserted is formed in the second bottom surface 52e of the second housing recess 52. Further, the first bottom surface 51 e of the first accommodating recess 51 is disposed closer to the second leg portion 22 b than the end surface of the third core 23 on the first leg portion 21 b side. That is, the part on the first leg 21 b side of the third core 23 protrudes from the third accommodation recess 53 to the first accommodation recess 51. The interposition part 21f and the first bottom face 51e are in contact with each other, and a gap 54 is formed between the end face 21e of the first leg part 21b and the third core 23.

Next, the operation of the third embodiment will be described.
Even if leakage magnetic flux M2 is generated around the first gap G1 and the second gap G2 from the magnetic core 20, the leakage magnetic flux M2 is linked to the interposition portions 21f and 22f, so that the first gap G1 and the second gap G2 Leakage magnetic flux M <b> 2 generated around is difficult to interlink with coil 30.

Therefore, according to the third embodiment, in addition to the same effects as the effects (1) and (2) of the first embodiment, the following effects can be obtained.
(4) On the end surface 21e of the first leg portion 21b and the end surface 22e of the second leg portion 22b, interposition portions 21f and 22f interposed between the first gap G1 or the second gap G2 and the coil 30 protrude. ing. According to this, since the leakage magnetic flux M2 generated around the first gap G1 or the second gap G2 is linked to the interposition portions 21f and 22f, the leakage generated around the first gap G1 or the second gap G2. The magnetic flux M2 becomes difficult to interlink with the coil 30. Therefore, the leakage magnetic flux M2 linked to the coil 30 can be reduced.

In addition, you may change the said embodiment as follows.
In the first to third embodiments, it is sufficient that at least a part of the first leg 21b is accommodated in the first accommodation recess 51.

In the first to third embodiments, it is sufficient that at least a part of the second leg portion 22b is accommodated in the second accommodation recess 52.
In the second embodiment, the shape of the contact portion 46 is not particularly limited. For example, the end surface 46b of the contact portion 46 extends in a direction perpendicular to the third inner surface 53a. It may be.

In the second embodiment, only one contact portion 46 may be provided on the third inner surface 53a, or three or more may be provided.
In the third embodiment, the interposition part 22f may be eliminated.

  In the third embodiment, the interposition part 21f may not extend over the entire outer edge of the end surface 21e of the first leg part 21b. Therefore, the interposition part 21f may not cover the entire outer periphery of the third core 23 on the first core 21 side, and may cover a part of the outer edge of the third core 23 on the first core 21 side.

  In the third embodiment, the interposition part 22f may not extend over the entire outer edge of the end surface 22e of the second leg part 22b. Therefore, the interposition part 22f may not cover the entire outer periphery of the third core 23 on the second core 22 side, and may cover a part of the outer edge of the third core 23 on the second core 22 side.

  In the third embodiment, the sum of the gap length L1 of the first gap G1 and the gap length L2 of the second gap G2 and the distance L3 between the interposition portions 21f and 22f may be the same.

  In the third embodiment, the inner peripheral surface 21r of the interposition part 21f may have a tapered shape (C chamfered shape) extending linearly in a direction oblique to the end surface 21e of the first core 21. Similarly, the inner peripheral surface 22r of the interposition part 22f may have a tapered shape (C chamfered shape) extending linearly in a direction oblique to the end surface 22e of the second core 22.

  In the third embodiment, the inner peripheral surface 21r of the interposition part 21f may extend in a direction orthogonal to the end surface 21e of the first core 21. Similarly, the inner peripheral surface 22r of the interposition part 22f may extend in a direction orthogonal to the end surface 22e of the second core 22.

  In each of the above embodiments, an adhesive is applied between the third bottom surface 53e of the third housing recess 53 and the third core 23, and the third core 23 is adhered to the third bottom surface 53e by the adhesive. Accordingly, the third core 23 may be positioned in the third accommodating recess 53.

  (Circle) in each said embodiment, the 1st core 21 and the 2nd core 22 do not need to be the same shape. For example, the length of the first leg portion 21 b of the first core 21 may be different from the length of the second leg portion 22 b of the second core 22. For example, the width H1 of the first leg 21b and the width H2 of the second leg 22b may be different.

In each of the above embodiments, the material of the third core 23 may be different from the material of the first core 21 and the material of the second core 22.
In each of the above embodiments, the first core 21 and the second core 22 may be, for example, an E-type core.

(Circle) in each said embodiment, the induction | guidance | derivation apparatus 11 may have five or more cores.
(Circle) in each said embodiment, the induction | guidance | derivation apparatus 11 may have three or more coil elements.

In each of the above embodiments, each coil element 31 may be a wound round wire.
(Circle) in each said embodiment, you may apply the induction | guidance | derivation apparatus 11 other than a reactor (for example, transformer).

  In each of the above embodiments, the reactor device may be other than a vehicle-mounted device.

  G1 ... 1st gap, G2 ... 2nd gap, 11 ... Induction device, 20 ... Magnetic core, 21 ... 1st core, 21b ... 1st leg part, 21e ... End surface, 21f ... Interposition part, 22 ... 2nd core, 22b ... second leg, 22e ... end face, 23 ... third core, 30 ... coil, 40 ... bobbin, 45 ... bottom wall, 46 ... contact portion, 51 ... first housing recess, 51a ... first inner surface, 51e ... 1st bottom surface, 52 ... 2nd accommodation recessed part, 52a ... 2nd inner surface, 52e ... 2nd bottom surface, 53 ... 3rd accommodation recessed part, 53a ... 3rd inner surface, 53e ... 3rd bottom surface, 54 ... Air gap.

Claims (3)

A magnetic core forming a magnetic path;
A coil wound around the magnetic core;
A resin bobbin that insulates the magnetic core and the coil;
The magnetic core is
A first core having a first leg;
A second core having a second leg;
A third core disposed between an end face of the first leg and an end face of the second leg,
A first gap between the end face of the first leg and the third core, and a second gap between the end face of the second leg and the third core;
The coil is wound around from the first leg portion to the second leg portion, and the cross-sectional area where the magnetic flux in the third core is linked is the same as that in the first leg portion and the second leg portion. An induction device in which the magnetic flux is smaller than the cross-sectional area where it is linked,
The bobbin is
A first accommodating recess for accommodating at least a part of the first leg,
A second receiving recess in which at least a part of the second leg is received;
A third receiving recess that communicates with the first receiving recess and receives at least a portion of the third core;
The first housing recess has a first inner surface located in a direction orthogonal to the winding center axis of the coil,
The second housing recess has a second inner surface located in a direction orthogonal to the winding center axis of the coil,
The third housing recess has a third inner surface located in a direction orthogonal to the winding center axis of the coil,
The third inner surface is disposed closer to the axis of the first leg and the second leg than the first inner surface and the second inner surface,
The first bottom surface of the first housing recess and the third inner surface are continuous,
The bottom wall having both the second bottom surface of the second housing recess and the third bottom surface of the third housing recess in the bobbin forms the second gap,
The induction device, wherein the first core and the first bottom surface are in contact with each other, and a gap as the first gap is formed between an end surface of the first leg portion and the third core. .   2. The abutting portion that protrudes between an end surface of the first leg portion and the third core and abuts against the third core protrudes from the third inner surface. The induction device described.   The induction device according to claim 1 or 2, wherein an intervening portion interposed between the first gap and the coil protrudes from an end surface of the first leg portion.