Inductors

Abstract

To adjust a magnetic resistance of each coil attaching point to a desired magnitude without preparing a gap between core divided bodies.SOLUTION: An inductor includes a core and an inductor. The core includes coil attaching part extending in a Y direction while aligning in an X direction. One coil is externally fitted to each coil attaching part. The core is formed in a plurality of core divided bodies, and arranged without preparing a gap between the core divided bodies. Positions of end faces in a Z direction of each coil attaching part are aligned in a Z direction. A position of an end face of a prescribed coil attaching part in a Z+ direction and a position of an end face of another coil attaching point in the Z+ direction are different in the Z direction. When viewed in the Y direction, a cross-section of the prescribed coil attaching part and a cross-section of another coil attaching part are different from each other.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to an inductor including a core having coil attachment portions arranged in a predetermined direction, and coils fitted onto each of the coil attachment portions. [Background technology]

[0002] Some inductors have a core that is divided into a number of core segments, and a gap is provided between the core segments at each coil mounting portion, thereby adjusting the magnetic resistance at each coil mounting portion to the desired value. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2017-195726 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, the inventors have noticed the following points: When adjusting the magnetic resistance to a desired value as described above, a process of inserting and bonding a member that forms a gap is required when assembling the inductor, which increases the number of processes and labor. Also, when the thickness of the gap to be controlled is thin, it is difficult to adjust the thickness to a desired value with high precision.

[0005] The present invention has been made in consideration of the above circumstances, and has an object to adjust the magnetic resistance at each coil attachment portion to a desired value without providing a gap between the core segments. [Means for solving the problem]

[0006] The inventors have found that the above object can be achieved by adjusting the position of one end of each coil attachment part based on the position of the other end in a cross-sectional view, thereby adjusting the cross-sectional area of ​​each coil attachment part to a desired size, and have arrived at the present invention. The present invention relates to the following inductors (1) to (4).

[0007] (1) An inductor including a core having coil attachment parts extending in a predetermined Y direction arranged in an X direction perpendicular to the Y direction, and a coil fitted onto each of the coil attachment parts, The core is divided into a plurality of core segments, and the core segments are arranged in contact with each other without providing any gaps between the core segments. The positions of the end faces of the coil attachment portions on the Z-direction side, which is one side of the Z direction perpendicular to the X direction and the Y direction, are aligned in the Z direction, a position of an end face of at least a certain coil mounting portion on the Z+ direction side as an opposite side to the Z- direction and a position of an end face of another coil mounting portion on the Z+ direction side are different from each other in the Z direction, When viewed in the Y direction, a cross-sectional area of ​​the predetermined coil mounting portion and a cross-sectional area of ​​the other coil mounting portion are different from each other. Inductor.

[0008] In this configuration, by adjusting the position of the end face of each coil mounting part on the Z+ side based on the position of the end face of each coil mounting part on the Z- side, the cross-sectional area of ​​each coil mounting part can be adjusted to a desired size, and the magnetic resistance of each coil mounting part can be adjusted to a desired size without providing a gap between the core segments.

[0009] (2) The core has a first coil mounting portion, a second coil mounting portion, and a third coil mounting portion as the coil mounting portion, The position of the end face on the Z+ direction side of each of the coil mounting parts is set so that the magnetic resistances of a path from the first coil mounting part through the second coil mounting part and returning to the first coil mounting part, a path from the first coil mounting part through the third coil mounting part and returning to the first coil mounting part, and a path from the second coil mounting part through the third coil mounting part and returning to the second coil mounting part are equal. The inductor according to (1) above.

[0010] According to this configuration, by making the magnetic resistance of the three paths uniform, it is possible to easily cancel out the DC components of the magnetic flux passing through each path, thereby efficiently suppressing magnetic saturation in the core.

[0011] (3) The inductor according to (1) or (2), further comprising a cooling section for cooling each of the coils, the cooling section being disposed on the Z-direction side of the core and each of the coils.

[0012] According to this configuration, the cooling section is provided on the Z-direction side of the end faces of the coil mounting parts aligned in the Z-direction. This allows each coil to be cooled. In addition, the following effects are also obtained. If the centers of the coil mounting parts in the Z-direction are aligned in the Z-direction, rather than the end faces on the Z-direction side of the coil mounting parts, the following problem occurs. That is, compared to the Z-direction end faces of the coil mounting parts with the widest width in the Z-direction, the Z-direction end faces of the other coil mounting parts are farther away from the cooling section. As a result, compared to the Z-direction end of the coil fitted to the former coil mounting part, the Z-direction end of the coil fitted to the latter coil mounting part is farther away from the cooling section. In this respect, according to this configuration, each coil mounting part becomes the coil mounting part closest to the cooling section. Therefore, each coil can be efficiently cooled.

[0013] (4) The coil includes a first coil fitted around the first coil mounting portion, a second coil fitted around the second coil mounting portion, and a third coil fitted around the third coil mounting portion, the first coil is part of a first chopper circuit that boosts a voltage supplied thereto; the second coil is part of a second chopper circuit that boosts a voltage supplied thereto; the third coil is part of a third chopper circuit that boosts a voltage supplied thereto; The first coil, the second coil, and the third coil are electrically connected in parallel to each other. The inductor according to (2) above.

[0014] According to this configuration, for example, in a three-phase magnetically coupled inductor constituting a part of a boost chopper, the effects of the configurations (1) to (3) above can be obtained. Moreover, this configuration is not limited to a three-phase configuration, and is similarly applicable to an inductor sharing multiple magnetic circuits of four or more phases. Effect of the Invention

[0015] As described above, the configuration of (1) above makes it possible to adjust the magnetic resistance at each coil attachment portion to a desired value without providing a gap between the core segments. Furthermore, the configurations of (2) to (4) above, which refer to (1) above, each provide additional effects. [Brief description of the drawings]

[0016] [Figure 1] FIG. 1 is a circuit diagram of a first embodiment. [Diagram 2] 11 is a graph showing changes in current flowing through each coil. [Diagram 3] FIG. 2 is a plan view showing an inductor. [Figure 4] FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. [Diagram 5] FIG. 13 is a plan view showing an inductor of a comparative example. [Figure 6] 6 is a cross-sectional view taken along line VI-VI in FIG. 5. [Figure 7] FIG. 11 is a circuit diagram of a second embodiment. [Figure 8] FIG. 11 is a circuit diagram of a third embodiment. [Figure 9] FIG. 2 is a plan view showing an inductor. [Figure 10] 10 is a cross-sectional view taken along the line XX in FIG. 9. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. However, the present invention is not limited to the following embodiment, and can be appropriately modified and implemented without departing from the spirit of the present invention.

[0018] [First embodiment] 1, the inductor 60 of this embodiment constitutes a part of a three-phase boost chopper 100. The three-phase boost chopper 100 includes input terminals iTp, iTn, an input side capacitor Cpi, a core 40, three-phase chopper circuits Bu, Bv, Bw, an output side capacitor Cpo, and output terminals oTp, oTn.

[0019] The input terminals iTp, iTn include a positive input terminal iTp and a negative input terminal iTn. The positive terminal of the battery Bt is electrically connected to the positive input terminal iTp, and the negative terminal of the battery Bt is electrically connected to the negative input terminal iTn. Hereinafter, the voltage supplied from the battery Bt to the input terminals iTp, iTn is referred to as the "input voltage."

[0020] The three-phase chopper circuits Bu, Bv, Bw include a first chopper circuit Bu, a second chopper circuit Bv, and a third chopper circuit Bw. The first chopper circuit Bu has a first coil CLu, a first switch Su, and a first diode Du. The second chopper circuit Bv has a second coil CLv, a second switch Sv, and a second diode Dv. The third chopper circuit Bw has a third coil CLw, a third switch Sw, and a third diode Dw.

[0021] Hereinafter, the first coil CLu, the second coil CLv, and the third coil CLw will be collectively referred to as “coils CLu, CLv, and CLw.” The inductor 60 includes a core 40, and coils CLu, CLv, and CLw fitted around the core 40.

[0022] Hereinafter, the current flowing through the first coil CLu will be referred to as the "first coil current Iu," the current flowing through the second coil CLv will be referred to as the "second coil current Iv," and the current flowing through the third coil CLw will be referred to as the "third coil current Iw." Additionally, the first coil current Iu, the second coil current Iv, and the third coil current Iw will be collectively referred to as the "coil currents Iu, Iv, Iw."

[0023] Hereinafter, the magnetic flux flowing along the core 40 will be referred to as the core magnetic flux. Furthermore, the core magnetic flux generated by the first coil current Iu will be referred to as the "first coil magnetic flux φu," the core magnetic flux generated by the second coil current Iv will be referred to as the "second coil magnetic flux φv," and the core magnetic flux generated by the third coil current Iw will be referred to as the "third coil magnetic flux φw." Furthermore, the first coil magnetic flux φu, the second coil magnetic flux φv, and the third coil magnetic flux φw will be collectively referred to as the "coil magnetic flux φu, φv, φw."

[0024] Next, the first chopper circuit Bu will be described in detail. One end of the first coil CLu is electrically connected to the positive input terminal iTp of the entire three-phase boost chopper 100 and the positive terminal of the input side capacitor Cpi. The other end of the first coil CLu is electrically connected to the positive terminal of the first switch Su and the anode terminal of the first diode Du. The negative terminal of the first switch Su is electrically connected to the negative input terminal iTn of the entire three-phase boost chopper 100, the negative terminal of the input side capacitor Cpi, the negative terminal of the output side capacitor Cpo, and the negative output terminal oTn of the entire three-phase boost chopper 100. The cathode terminal of the first diode Du is electrically connected to the positive terminal of the output side capacitor Cpo and the positive output terminal oTp of the entire three-phase boost chopper 100. The first switch Su is a semiconductor switch such as a transistor, a MOSFET, or an IGBT.

[0025] When the first switch Su is turned ON, the first coil current Iu increases, storing magnetic energy in the first coil CLu, and when the first switch Su is turned OFF, the magnetic energy is released, causing a voltage higher than the input voltage to be output from the other end of the first coil CLu. As a result, the first chopper circuit Bu boosts the input voltage.

[0026] The details of the second chopper circuit Bv are similar to those of the first chopper circuit Bu above, except that "first" is replaced with "second" and the symbols are replaced with the corresponding ones. The details of the third chopper circuit Bw are similar to those of the first chopper circuit Bu above, except that "first" is replaced with "third" and the symbols are replaced with the corresponding ones.

[0027] As described above, the first to third coils CLu, CLv, CLw are electrically connected in parallel to one another, and the first to third chopper circuits Bu, Bv, Bw boost the input voltage in parallel to one another.

[0028] Next, referring to Fig. 2, the control of each of the three-phase chopper circuits Bu, Bv, Bw will be described. Hereinafter, the period from when the switch is turned ON, to when it is turned OFF, and then when it is turned ON again will be referred to as "one cycle." Each of the three-phase chopper circuits Bu, Bv, Bw is controlled with a phase shift of one-third of a cycle from each other. In other words, the timing at which the switches Su, Sv, Sw are turned ON between the respective phases is shifted by one-third of a cycle from each other. Similarly, the timing at which they are turned OFF is also shifted by one-third of a cycle from each other.

[0029] In each phase, when the switches Su, Sv, Su are turned ON, the coil currents Iu, Iv, Iw of the corresponding phase increase. On the other hand, in each phase, when the switches Su, Sv, Su are turned OFF, the coil currents Iu, Iv, Iw of the corresponding phase decrease. From the above, the coil currents Iu, Iv, Iw of each phase include DC components IuD, IvD, IwD and AC components IuA, IvA, IwA, respectively. The magnitudes of the DC components IuD, IvD, IwD of the coil currents of each phase are controlled to be equal to each other.

[0030] Next, the inductor 60 will be described with reference to FIG. 3. Hereinafter, the three mutually orthogonal directions are referred to as the "X direction", "Y direction" and "Z direction". One of the X directions is referred to as the "X- direction", and the opposite direction is referred to as the "X+ direction". One of the Y directions is referred to as the "Y- direction", and the opposite direction is referred to as the "Y+ direction". As shown in FIG. 4, one of the Z directions is referred to as the "Z- direction", and the opposite direction is referred to as the "Z+ direction". In this embodiment, the Z+ direction is the upward direction. However, the Z+ direction may be a direction oblique to the upward direction, a horizontal direction, a downward direction, or the like.

[0031] The core 40 has three coil mounting parts 45u, 45v, 45w, and a first connection part 41 and a second connection part 49 that connect them to each other. The three coil mounting parts 45u, 45v, 45w include a first coil mounting part 45u, a second coil mounting part 45v, and a third coil mounting part 45w. The three coil mounting parts 45u, 45v, 45w each extend in the Y direction and are arranged in the X direction. The first connection part 41 connects the ends of the three coil mounting parts 45u, 45v, 45w on the Y+ direction side to each other. The second connection part 49 connects the ends of the three coil mounting parts 45u, 45v, 45w on the Y- direction side to each other.

[0032] Specifically, the core 40 is divided into a first core divided body 40a and a second core divided body 40b. The first core divided body 40a includes a first connection portion 41 and the Y+ direction halves of each of the three coil attachment portions 45u, 45v, and 45w. The second core divided body 40b includes a second connection portion 49 and the Y- direction halves of each of the three coil attachment portions 45u, 45v, and 45w.

[0033] On the inside of each of the three coils CLu, CLv, and CLw, the end face of the first core divided body 40a facing the Y- direction and the end face of the second core divided body 40b facing the Y+ direction are in contact with each other. In other words, the core divided bodies 40a, 40b are in contact with each other without providing a gap between them. As a result, the first coil CLu is fitted onto the first coil mounting portion 45u, the second coil CLv is fitted onto the second coil mounting portion 45v, and the third coil CLw is fitted onto the third coil mounting portion 45w.

[0034] Hereinafter, in the core 40, a path from the first coil mounting portion 45u through the second coil mounting portion 45v and back to the first coil mounting portion 45u is referred to as the "first second path 45u-45v". In addition, in the core 40, a path from the first coil mounting portion 45u through the third coil mounting portion 45w and back to the first coil mounting portion 45u is referred to as the "first third path 45u-45w". In addition, in the core 40, a path from the second coil mounting portion 45v through the third coil mounting portion 45w and back to the second coil mounting portion 45v is referred to as the "second third path 45v-45w". In addition, the first second path 45u-45v, the first third path 45u-45w, and the second third path 45v-45w are collectively referred to as the "three paths 45u-45v, 45u-45w, 45v-45w".

[0035] 4, the three coil attachment portions 45u, 45v, 45w have the same length in the X direction. The positions of the end faces on the Z- direction side of the three coil attachment portions 45u, 45v, 45w are aligned in the Z direction.

[0036] The positions of the end faces of the first coil mounting portion 45u and the third coil mounting portion 45w on the Z+ direction side are equal to each other. On the other hand, the position of the end face of the second coil mounting portion 45v on the Z+ direction side is located on the Z- direction side with respect to the positions of the end faces of the first coil mounting portion 45u and the third coil mounting portion 45w on the Z+ direction side. Therefore, as shown in FIG. 4, the cross-sectional area of ​​the second coil mounting portion 45v is smaller than the cross-sectional area of ​​the first coil mounting portion 45u and the cross-sectional area of ​​the third coil mounting portion 45w when viewed in the Y direction.

[0037] As a result, in the core 40 shown in Fig. 3, the magnetic resistance of the first second path 45u-45v, the magnetic resistance of the first third path 45u-45w, and the magnetic resistance of the second third path 45v-45w are all equal. Therefore, the DC components of the core magnetic flux are offset in each path 45u-45v, 45u-45w, and 45v-45w. The reason for this will be described later.

[0038] 4, a cooling unit 50 is provided on the Z-direction side of the core 40 and the three coils CLu, CLv, and CLw. The cooling unit 50 cools the core 40 and the three coils CLu, CLv, and CLw. The cooling unit 50 is provided with, for example, a flow path 54, through which a refrigerant 55 such as cooling water flows.

[0039] Next, with reference to FIG. 3, the reason why the DC components of the core magnetic flux are cancelled out in each of the paths 45u-45v, 45u-45w, and 45v-45w will be described.

[0040] In the first coil attachment portion 45u, the entire first coil magnetic flux φu flows, and in the opposite direction, a part of the second coil magnetic flux φv and a part of the third coil magnetic flux φw flow. At this time, as described above, since the magnetic resistances of the first second path 45u-45v and the second third path 45v-45w are equal to each other, the second coil magnetic flux φv is neatly divided into the first second path 45u-45v and the second third path 45v-45w. Also, since the magnetic resistances of the first third path 45u-45w and the second third path 45v-45w are equal to each other, the third coil magnetic flux φw is neatly divided into the first third path 45u-45w and the second third path 45v-45w.

[0041] For the above reasons, the entire first coil magnetic flux φu flows in the first coil attachment portion 45u, and exactly half of the second coil magnetic flux φv and exactly half of the third coil magnetic flux φw flow in the opposite direction. Therefore, if the first coil magnetic flux φu, the second coil magnetic flux φv, and the third coil magnetic flux φw are equal in magnitude, they are cancelled out neatly without excess or deficiency.

[0042] In this regard, as described above, the DC components IuD, IvD, and IwD of the coil currents are equal to each other, as shown in FIG. 2. Therefore, the DC components of the coil magnetic fluxes φu, φv, and φw generated by them are also equal to each other. Therefore, the DC component of the core magnetic flux flowing through the first coil mounting portion 45u shown in FIG. 3 is neatly canceled out without excess or deficiency. Similarly, the DC components of the core magnetic fluxes w flowing through the second coil mounting portion 45v and the third coil mounting portion 45w are neatly canceled out without excess or deficiency.

[0043] Hereinafter, the comparative embodiment will be referred to as the comparative embodiment shown in Fig. 6, which is modified from the state of the present embodiment shown in Fig. 4. That is, in this comparative embodiment, the position of the end face on the Y+ direction side of the second coil mounting part 45v is aligned with the positions of the end faces on the Y+ direction side of the first coil mounting part 45u and the third coil mounting part 45w. Therefore, as shown in Fig. 6, the cross-sectional areas of the three coil mounting parts 45u, 45v, and 45w are equal to each other when viewed in the Y direction.

[0044] 5, in the comparative example, a gap Gp is ​​provided between the first core division 40a and the second core division 40b. The gap Gp at the second coil attachment portion 45v is larger than the gap Gp at the first coil attachment portion 45u and the third coil attachment portion 45w. As a result, the magnetic resistances of the three paths 45u-45v, 45u-45w, and 45v-45w are uniform.

[0045] The configuration and effects of this embodiment will be summarized below in comparison with the comparative embodiment described above.

[0046] 5, the magnetic resistance in each of the paths 45u-45v, 45u-45w, and 45v-45w can be adjusted to a desired value by adjusting the size of the three gaps Gp. However, when assembling the inductor 60, a process of inserting and bonding the members that form the gaps Gp is ​​required, which increases the number of processes and labor. In addition, when the thickness of the gap Gp to be controlled is thin, it is difficult to adjust it to a desired size with high accuracy.

[0047] In this embodiment, as shown in Fig. 4, the position of the end of each coil mounting portion 45u, 45v, 45w in the Z+ direction is adjusted based on the position of the end of each coil mounting portion 45u, 45v, 45w in the Z- direction. This adjusts the cross-sectional area of ​​each coil mounting portion 45u, 45v, 45w to a desired size. This allows the magnetic resistance of each coil mounting portion 45u, 45v, 45w to be adjusted to a desired size without providing a gap between the core segments 40a, 40b, as shown in Fig. 3.

[0048] Furthermore, since no gap is provided, if the magnetic resistance of each of the coil mounting parts 45u, 45v, 45w is the same as when there is a gap, the length of one revolution in the circumferential direction can be reduced. In particular, the length of one revolution in the circumferential direction can be significantly reduced for the second coil mounting part 45v. As a result, the total length of each of the coils CLu, CLv, CLw can be reduced, and the total length of the second coil CLv can be reduced particularly significantly.

[0049] 3, the magnetic resistance of the first second path 45u-45v, the magnetic resistance of the first third path 45u-45w, and the magnetic resistance of the second third path 45v-45w are equal to each other. Therefore, as described above, it becomes easier to cancel out the DC components of the coil magnetic fluxes φu, φv, and φw in each path 45u-45v, 45u-45w, and 45v-45w. This makes it possible to efficiently suppress magnetic saturation and heat generation in the core 40.

[0050] As shown in FIG. 4, the cooling unit 50 is provided on the Z-direction side of the end faces of the coil mounting parts 45u, 45v, 45w aligned in the Z-direction. Therefore, the three coils CLu, CLv, CLw can be cooled evenly. In addition, the following effect is obtained. If the centers of the coil mounting parts 45u, 45v, 45w in the Z-direction are aligned in the Z-direction, rather than the end faces on the Z-direction side of the coil mounting parts 45u, 45v, 45w, the following problem occurs. That is, the end face in the Z-direction of the second coil mounting part 45v is farther away from the cooling unit 50 than the end faces in the Z-direction of the first and third coil mounting parts 45u, 45w, which have the largest width in the Z-direction. As a result, the end face in the Z-direction of the second coil CLv is farther away from the cooling unit 50 than the end faces in the Z-direction of the first and third coils CLu, CLw. In this regard, in the present embodiment, all of the coil attachment parts 45u, 45v, 45w become the coil attachment parts closest to the cooling part 50. Therefore, all of the coils CLu, CLv, CLw can be efficiently cooled.

[0051] 1, inductor 60 constitutes a part of three-phase boost chopper 100. Therefore, inductor 60 of three-phase boost chopper 100, the above-mentioned effects can be obtained.

[0052] [Second embodiment] Next, a second embodiment will be described. The following embodiment will be described based on the first embodiment, focusing on the differences, and descriptions of the same or similar aspects to the first embodiment will be omitted as appropriate.

[0053] 7, the inductor 60 of this embodiment constitutes a part of a noise filter 200. The noise filter 200 is interposed between a three-phase AC inverter 190 and a motor 210.

[0054] The noise filter 200 includes input terminals iTu, iTv, and iTw, a core 40, three-phase coils CLu, CLv, and CLw, six capacitors Cp, and output terminals oTu, oTv, and oTw. The input terminals iTu, iTv, and iTw include a first input terminal iTu, a second input terminal iTv, and a third input terminal iTw. The output terminals oTu, oTv, and oTw include a first output terminal oTu, a second output terminal oTv, and a third output terminal oTw.

[0055] The first input terminal iTu is electrically connected to the first output terminal oTu via the first coil CLu. The second input terminal iTv is electrically connected to the second output terminal oTv via the second coil CLv. The third input terminal iTw is electrically connected to the third output terminal oTw via the third coil CLw.

[0056] In the noise filter 200, each of the two input terminals iTu-iTv, iTv-iTw, and iTw-iTu is electrically connected to each other via a capacitor Cp. In the noise filter 200, each of the two output terminals oTu-oTv, oTv-oTw, and oTw-oTu is electrically connected to each other via a capacitor Cp.

[0057] According to this embodiment, in the inductor 60 of the noise filter 200, the magnetic resistance at each of the coil attachment portions 45u, 45v, 45w can be adjusted to a desired value without providing a gap between the divided core bodies 40a, 40b.

[0058] [Third embodiment] Next, a third embodiment will be described. As shown in Fig. 8, the inductor 70 of this embodiment constitutes a part of a transformer 300. The transformer 300 includes an input side full bridge circuit 330 and an output side full bridge circuit 380. The first coil CLu is electrically connected to the input side full bridge circuit 330, and the second coil CLv is electrically connected to the output side full bridge circuit 380. The number of turns of the second coil CLv is greater than the number of turns of the first coil CLu.

[0059] As shown in Fig. 9, the core 40 does not have the third coil mounting portion 45w in the embodiment in Fig. 1. The first connection portion 41 connects the Y+ direction ends of the first coil mounting portion 45u and the second coil mounting portion 45v to each other, and the second connection portion 49 connects the Y- direction ends of the first coil mounting portion 45u and the second coil mounting portion 45v to each other.

[0060] 10, when viewed in the Y direction, the cross-sectional area of ​​the second coil attachment portion 45v is smaller than the cross-sectional area of ​​the first coil attachment portion 45u, similarly to the first embodiment.

[0061] According to this embodiment, the first coil mounting portion 45u and the second coil mounting portion 45v can satisfy their respective priorities. That is, for the first coil mounting portion 45u shown in Fig. 9, since the number of turns of the first coil CLu is relatively small, it is desired to prioritize increasing the cross-sectional area to suppress the magnetic resistance of the entire core 40 over suppressing the cross-sectional area to suppress the total length of the first coil CLu. On the other hand, for the second coil mounting portion 45v, since the number of turns of the second coil CLv is relatively large, it is desired to prioritize suppressing the cross-sectional area to suppress the total length of the second coil CLv.

[0062] In this regard, according to the present embodiment, as shown in Fig. 10, in the first coil mounting portion 45u, the end face on the Z+ direction side is relatively closer to the Z+ direction, and the cross-sectional area is relatively larger. On the other hand, in the second coil mounting portion 45v, the end face on the Z+ direction side is relatively closer to the Z- direction, and the cross-sectional area is relatively smaller. As a result, the first coil mounting portion 45u and the second coil mounting portion 45v can satisfy their respective priorities.

[0063] As described above, according to this embodiment, as shown in FIG. 9, in the inductor 60 of the transformer 300, the magnetic resistance at each coil mounting portion 45u, 45v can be adjusted to the desired magnitude without providing a gap between the core segments 40a, 40b.

[0064] [Other embodiments] The above-described embodiments can be modified, for example, as follows. The core 40 may be divided into three or more parts. The core 40 may be divided at a position different from that in the first embodiment and the like. The number of coil attachment parts may be four or more, and the number of coils may be four or more. In the first embodiment, the three-phase chopper circuits Bu, Bv, Bw may be controlled in the same phase as each other. [Explanation of symbols]

[0065] 40 cores 40a First core division 40b Second core segment 45u 1st coil mounting part 45v Second coil mounting part 45w 3rd coil mounting part 50 Cooling section 60 Inductor 70 Inductor 100 3-phase boost chopper Bu 1st chopper circuit Bv Second chopper circuit Bw 3rd chopper circuit CLu 1st coil CLv 2nd coil CLw 3rd coil Gp Gap

Claims

1. An inductor comprising: a core having coil attachment parts extending in a predetermined Y direction, the coil attachment parts being arranged in an X direction perpendicular to the Y direction; and a coil fitted onto each of the coil attachment parts, The core is divided into a plurality of core segments, and the core segments are arranged in contact with each other without providing any gaps between the core segments. The positions of end faces of the coil attachment portions on a Z-direction side, which is one side of a Z direction perpendicular to the X direction and the Y direction, are aligned in the Z direction, a position of an end face on the Z+ direction side, which is the opposite side to the Z- direction, of at least a certain one of the coil mounting portions and a position of an end face on the Z+ direction side of another of the coil mounting portions are different from each other in the Z direction; When viewed in the Y direction, a cross-sectional area of ​​the predetermined coil mounting portion and a cross-sectional area of ​​the another coil mounting portion are different from each other. Inductor.

2. The core has a first coil mounting portion, a second coil mounting portion, and a third coil mounting portion as the coil mounting portion, The position of the end face on the Z+ direction side of each of the coil mounting portions of the core is set so that the magnetic resistances of a path from the first coil mounting portion through the second coil mounting portion and returning to the first coil mounting portion, a path from the first coil mounting portion through the third coil mounting portion and returning to the first coil mounting portion, and a path from the second coil mounting portion through the third coil mounting portion and returning to the second coil mounting portion are equal to each other.

2. The inductor of claim 1.

3. 3. The inductor according to claim 1, further comprising a cooling section for cooling each of said coils, said cooling section being disposed on the Z-direction side of said core and each of said coils.

4. the coils include a first coil fitted around the first coil mounting portion, a second coil fitted around the second coil mounting portion, and a third coil fitted around the third coil mounting portion, the first coil is part of a first chopper circuit that boosts a voltage supplied thereto; the second coil is part of a second chopper circuit that boosts a voltage supplied thereto; the third coil is part of a third chopper circuit that boosts a voltage supplied thereto; The first coil, the second coil, and the third coil are electrically connected in parallel to each other. The inductor according to claim 2 .

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