Magnetic coupling type reactor and step-up circuit

Abstract

To reduce interlinking of leakage magnetic flux with windings while suppressing an increase in size.SOLUTION: A reactor core of a magnetically coupled reactor includes a first outer core portion having two first legs extending in a first direction and a first base connecting the two first legs, a second outer core portion having two second legs extending in a first direction and a second base connecting the two second legs, and an intermediate core portion extending integrally so as to be continuous in the first direction and connecting the first leg and the second leg, and a first connection portion connecting the first leg and the intermediate core portion is located within a range in which a first coil portion is wound in the first direction, and a second connection portion connecting the second leg and the intermediate core portion is located within a range in which the second coil portion is wound in the first direction.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present disclosure relates to a magnetic coupling reactor and a boost circuit.

Background Art

[0002] Patent Document 1 describes a magnetic coupling reactor mounted on an automobile such as a hybrid vehicle or an electric vehicle. The reactor core of this reactor has two U-shaped split cores, and the end faces of these split cores are abutted against each other to form a closed magnetic circuit. Further, in Patent Document 1, a plurality of phase coils are wound around one reactor core, and the direct current magnetic flux is canceled by making the directions of the mutual magnetic fluxes opposite to each other.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the magnetic coupling reactor described in Patent Document 1, magnetic flux leaks from the portion where the end faces of the reactor core are abutted against each other, and this leakage magnetic flux links with the winding wires of the coil, so that there is a possibility that eddy currents are generated in the winding wires. The generation of such eddy currents causes a bias in the current density of the winding wires and may cause a temperature rise. Therefore, there is a problem that measures such as increasing the size of the magnetic coupling reactor are required.

[0005] The present disclosure has been made in view of such problems, and an object thereof is to provide a magnetic coupling reactor and a boost circuit capable of reducing the leakage magnetic flux from linking with the winding wires while suppressing an increase in size.

Means for Solving the Problems

[0006] A magnetic coupling reactor according to one aspect of the present disclosure includes a reactor core forming a closed magnetic circuit, a first coil portion wound around the reactor core in a split manner, and a second coil portion wound around the reactor core at a position spaced apart from the first coil portion in a first direction. The reactor core includes a first outer core portion having two first leg portions extending in the first direction and a first base portion connecting the two first leg portions on a first side in the first direction, a second outer core portion having two second leg portions extending in the first direction and a second base portion connecting the two second leg portions on a second side in the first direction, and two intermediate core portions arranged side by side in a second direction intersecting the first direction and continuously extending integrally in the first direction to connect the first leg portions and the second leg portions. The first coil portion and the second coil portion are wound around at least the two intermediate core portions arranged side by side in the second direction. A first connection portion connecting the first leg portion and the intermediate core portion is located within a range where the first coil portion is wound in the first direction, and a second connection portion connecting the second leg portion and the intermediate core portion is located within a range where the second coil portion is wound in the first direction. The first coil part and the second coil part are wound in a direction such that the direction of the magnetic flux generated in the closed magnetic circuit by the second coil part is opposite to the direction of the magnetic flux generated in the closed magnetic circuit by the first coil part, and the intermediate core part does not have a cut extending in a direction intersecting the first direction in the middle of the first direction. 。

Advantages of the Invention

[0007] According to the above aspect, it is possible to reduce the leakage magnetic flux from linking with the winding while suppressing the increase in size.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Best Mode for Carrying Out the Invention

[0009] Hereinafter, an embodiment of the present disclosure will be described in detail with reference to FIGS. 1 to 4. <Boost Circuit> As shown in FIG. 1, the magnetic coupling reactor 10 of the present embodiment is a magnetic coupling reactor used in an interleaved boost circuit 100. The boost circuit 100 of the present embodiment is built in, for example, an inverter that drives an electric motor mounted on a hybrid hydraulic excavator or the like, and boosts the terminal voltage V1 of a capacitor or the like to the required voltage V2 by the inverter.

[0010] The boost circuit 100 includes a smoothing capacitor 11A provided between input terminals Ti1 and Ti2, a smoothing capacitor 11B provided between output terminals To1 and To2, and a polyphase (biphase in this embodiment) boost chopper circuit 14. These two-phase boost chopper circuits 14 are composed of switching elements 12 and freewheeling diodes 13 that respectively constitute a high-side arm 15 and a low-side arm 16, and a magnetic coupling reactor 10 connected between the switching element 12 of the high-side arm 15 and the switching element 12 of the low-side arm 16. These two-phase boost chopper circuits 14 are driven with their phases shifted from each other.

[0011] <Magnetic Coupling Reactor> As shown in FIG. 2, the magnetic coupling reactor 10 includes a first coil portion 21 and a second coil portion 22 used in a two-phase boost chopper circuit 14, and a single reactor core 23 that forms a closed magnetic circuit. The reactor core 23 magnetically couples the first coil portion 21 and the second coil portion 22. The first coil portion 21 and the second coil portion 22 are wound around the reactor core 23 so as to cancel each other's magnetic fluxes (in FIG. 3, examples of the directions of the magnetic fluxes are indicated by arrows). The magnetic coupling reactor 10 of the present embodiment is a reactor used in a hybrid hydraulic excavator or the like, and a large current flows through it as compared with a magnetic coupling reactor used in a vehicle such as an automobile. Therefore, the magnetic coupling reactor 10 of the present embodiment is larger in size than a reactor used in a vehicle such as an automobile.

[0012] <Reactor core> As shown in FIGS. 3 and 4, the reactor core 23 includes a first outer core portion 31, a second outer core portion 32, and two intermediate core portions 33. In the following description, the first direction is referred to as "Dx", the second direction intersecting the first direction is referred to as "Dy", and the third direction intersecting the first direction Dx and the second direction Dy is referred to as "Dz". The reactor core 23 in the present embodiment is formed, for example, by laminating a plurality of electromagnetic steel sheets such as silicon steel sheets in the third direction Dz.

[0013] The first outer core portion 31 includes two first leg portions 35 and one first base portion 36. Both of the two first leg portions 35 extend in the first direction Dx. The two first leg portions 35 of the present embodiment have the same square prism shape and have the same length in the first direction Dx. The two first leg portions 35 are arranged to be spaced apart in the second direction Dy. The interval between the two first leg portions 35 in the second direction Dy is set according to the wire diameter of the first coil portion 21 or the like.

[0014] The first base 36 is disposed on the first side Dx1 in the first direction Dx of the two first legs 35 and is formed to extend in the second direction Dy between the two first legs 35. That is, the first base 36 connects the two first legs 35 on the first side Dx1 in the first direction Dx. The first base 36 in the present embodiment has a quadrangular prism shape extending in the second direction Dy. Further, the first base 36 is integrally formed with the first leg 35. In other words, no gap or the like is formed between the first leg 35 and the first base 36 and they are continuous. Thereby, the first outer core portion 31 forms a U shape when viewed from the third direction Dz. In the present embodiment, a case is exemplified in which the cross-sectional area of the first base 36 in a cross-section perpendicular to the second direction Dy is the same as the cross-sectional area of the first leg 35 in a cross-section perpendicular to the first direction Dx. Further, the end faces 35t of the two first legs 35 are planes perpendicular to the first direction Dx and face the second side Dx2 in the first direction Dx.

[0015] The second outer core portion 32 is formed symmetrically with the first outer core portion 31 in the first direction Dx. The second outer core portion 32 includes two second legs 37 and one second base 38. Both of the two second legs 37 extend in the first direction Dx. The two second legs 37 in the present embodiment have the same quadrangular prism shape as the first leg 35. The lengths of the two second legs 37 in the first direction Dx are the same. And these two second legs 37 are arranged spaced apart in the second direction Dy. The interval between the two second legs 37 in the second direction Dy is the same as the interval between the two first legs 35 in the second direction Dy.

[0016] The second base portion 38 connects the two second leg portions 37 on the second side Dx2 in the first direction Dx. In other words, the second base portion 38 is disposed on the second side Dx2 in the first direction Dx of the two second leg portions 37 and is formed to extend in the second direction Dy between the two second leg portions 37. The second base portion 38 in the present embodiment has a quadrangular prism shape extending in the second direction Dy, similar to the first base portion 36. Further, the second base portion 38 is integrally formed with the second leg portion 37. That is, no gap or the like is formed between the second leg portion 37 and the second base portion 38, and they are continuous. Thereby, the second outer core portion 32 forms a U shape when viewed from the third direction Dz. In the present embodiment, the case where the cross-sectional area of the second base portion 38 in a cross-section perpendicular to the second direction Dy is the same as the cross-sectional area of the second leg portion 37 in a cross-section perpendicular to the first direction Dx is illustrated. Also, the end faces 37t of the two second leg portions 37 are planes perpendicular to the first direction Dx and face the first side Dx1 in the first direction Dx.

[0017] The intermediate core portion 33 extends in the first direction Dx. The intermediate core portion 33 is continuously integrally formed in the first direction Dx. In other words, the intermediate core portion 33 does not have a break such as a joint surface extending in a direction intersecting the first direction Dx in the middle of the first direction Dx.

[0018] The intermediate core portion 33 connects the first leg portion 35 of the first outer core portion 31 and the second leg portion 37 of the second outer core portion 32 described above. Specifically, the intermediate core portion 33 connects the first leg portion 35 and the second leg portion 37 disposed at the same position in the second direction Dy. That is, two intermediate core portions 33 of the present embodiment are arranged side by side in the second direction Dy. Further, the intermediate core portion 33 of the present embodiment is formed to extend the first leg portion 35 and the second leg portion 37 in the first direction Dx. Specifically, the intermediate core portion 33 of the present embodiment has a quadrangular prism shape, and in a cross-section perpendicular to the first direction Dx, the cross-sectional area of the intermediate core portion 33 is the same as the cross-sectional areas of the first leg portion 35 and the second leg portion 37.

[0019] A first connecting portion 41 that connects the intermediate core portion 33 and the first leg portion 35, and a second connecting portion 42 that connects the intermediate core portion 33 and the second leg portion 37 in this embodiment are provided with a first separator 39. This first separator 39 forms a gap for increasing magnetic resistance and reducing magnetic saturation. The first separator 39 of this embodiment can use a material with excellent heat resistance such as epoxy or alumina. Note that the first separator 39 may be provided as needed.

[0020] <Coil> The first coil portion 21 and the second coil portion 22 are formed by winding a wire material such as a copper wire in a solenoid shape. The first coil portion 21 and the second coil portion 22 are divided and wound around a reactor core 23. The first coil portion 21 and the second coil portion 22 are divided and wound so as to extend over at least two intermediate core portions 33 (referred to as a first intermediate core portion 33A and a second intermediate core portion 33B in the following description) arranged side by side in the second direction Dy.

[0021] The first coil portion 21 of this embodiment has two first divided coil portions 21A and 21B connected in series. The first divided coil portion 21A is wound around at least the first intermediate core portion 33A, and the first divided coil portion 21B is wound around at least the second intermediate core portion 33B. The first divided coil portions 21A and 21B of this embodiment are each wound so as to extend over the first leg portion 35 of the first outer core portion 31 and the intermediate core portion 33 in the first direction Dx. Similarly, the second coil portion 22 of this embodiment has two second divided coil portions 22A and 22B connected in series. The second divided coil portion 22A is wound around at least the first intermediate core portion 33A, and the second divided coil portion 22B is wound around at least the second intermediate core portion 33B. The second divided coil portions 22A and 22B of this embodiment are each wound so as to extend over the second leg portion 37 of the second outer core portion 32 and the intermediate core portion 33 in the first direction Dx.

[0022] The winding directions of the windings of the two first divided coil parts 21A and 21B of the first coil part 21 are set to be in the same direction as the direction of the magnetic flux in the closed magnetic path of the reactor core 23 generated by these two first divided coil parts 21A and 21B. Similarly, the winding directions of the windings of the two second divided coil parts 22A and 22B of the second coil part 22 are set to be in the same direction as the direction of the magnetic flux in the closed magnetic path of the reactor core 23 generated by these two second divided coil parts 22A and 22B. On the other hand, the windings of the first divided coil parts 21A and 21B and the windings of the second divided coil parts 22A and 22B are wound in opposite directions so that the magnetic flux generated by the first divided coil parts 21A and 21B and the magnetic flux generated by the second divided coil parts 22A and 22B cancel each other out.

[0023] The first coil part 21 and the second coil part 22 of the present embodiment have the same number of turns. The two first divided coil parts 21A and 21B have the same number of turns as each other, and the two second divided coil parts 22A and 22B have the same number of turns as each other. The first coil part 21 and the second coil part 22 are arranged to be separated from each other in the first direction Dx. That is, the first divided coil part 21A and the second divided coil part 22A wound around the first intermediate core part 33A are separated from each other in the first direction Dx, and the first divided coil part 21B and the second divided coil part 22B wound around the second intermediate core part 33B are separated from each other in the first direction Dx. In the present embodiment, the distance between the first divided coil part 21A and the second divided coil part 22B wound around the first intermediate core part 33A is set to be the same as the distance between the first divided coil part 21B and the second divided coil part 22B wound around the second intermediate core part 33B.

[0024] The first connection portion 41 where the first leg portion 35 is connected to the intermediate core portion 33 is located within the range in which the first coil portion 21 is wound in the first direction Dx. Similarly, the second connection portion 42 where the second leg portion 37 is connected to the intermediate core portion 33 is located within the range in which the second coil portion 22 is wound in the first direction Dx. In other words, the first connection portion 41 is covered by the first coil portion 21 from the second direction Dy and the third direction Dz, and the second connection portion 42 is covered by the second coil portion 22 from the second direction Dy and the third direction Dz.

[0025] In the present embodiment, the first connection portion 41 is located at the intermediate portion 21C that is equidistant from both ends of the first coil portion 21 in the first direction Dx. Similarly, the case where the second connection portion 42 is located at the intermediate portion 22C that is equidistant from both ends of the second coil portion 22 in the first direction Dx is illustrated. Note that the first connection portion 41 is not limited to being located at the intermediate portion 21C. For example, it may be located on the intermediate portion 21C side of the first coil portion 21 rather than at both ends of the first coil portion 21 in the first direction Dx. Also, the first connection portion 41 may be located closer to the intermediate portion 21C of the first coil portion 21 than both ends of the first coil portion 21 in the first direction Dx. Similarly, the second connection portion 42 is not limited to being located at the intermediate portion 22C of the second coil portion 22. For example, it may be located on the intermediate portion 22C side rather than at both ends of the second coil portion 22 in the first direction Dx. Also, the second connection portion 42 may be located closer to the intermediate portion 22C of the second coil portion 22 than both ends of the second coil portion 22 in the first direction Dx.

[0026] <Function and effect> As described above, in the magnetic coupling reactor 10 of the present embodiment, the first coil portion 21 and the second coil portion 22 are split-wound so as to at least cross two intermediate core portions 33 arranged side by side in the second direction Dy. And the first connection portion 41 connected to the first leg portion 35 and the intermediate core portion 33 is located within the range where the first coil portion 21 is wound in the first direction Dx, and the second connection portion 42 connected to the second leg portion 37 and the intermediate core portion 33 is located within the range where the second coil portion 22 is wound in the first direction Dx. And the intermediate core portion 33 extends continuously and integrally in the first direction Dx. In this case, the first connection portion 41 and the second connection portion 42, which are the joints of the reactor core 23, are not arranged between the first coil portion 21 and the second coil portion 22. Therefore, it is possible to suppress the magnetic flux leaking from the joint of the reactor core 23 from linking with the ends of the first coil portion 21 and the second coil portion 22 in the first direction Dx, and reduce the eddy current generated in the first coil portion 21 and the second coil portion 22.

[0027] In the present embodiment, further, at least one of the first connection portion 41 and the second connection portion 42 has a first separator 39 that increases the magnetic resistance. When having the first separator 39 in this way, the leakage magnetic flux from the first connection portion 41 and the second connection portion 42 increases, but since the first connection portion 41 and the second connection portion 42 are located within the range where the first coil portion 21 and the second coil portion 22 are wound, the influence of the leakage magnetic flux from the first connection portion 41 and the second connection portion 42 having the first separator 39 can be effectively suppressed.

[0028] In this embodiment, furthermore, the direction of the magnetic flux generated by the second coil portion 22 is opposite to the direction of the magnetic flux generated by the first coil portion 21. In this case, as shown in FIG. 3, between the first coil portion 21 and the second coil portion 22 in the first direction Dx, the magnetic fluxes of each other cancel each other out. Therefore, it is possible to suppress the increase in the size of the reactor core 23. Also, at this time, for example, if there is a joint of the reactor core 23 between the first coil portion 21 and the second coil portion 22, the magnetic flux leaking from this joint particularly increases. However, since there is no joint of the reactor core 23 between the first coil portion 21 and the second coil portion 22, an increase in leakage magnetic flux can be suppressed.

[0029] In this embodiment, furthermore, for example, the coupling degree between the first coil portion 21 and the second coil portion 22 can be adjusted only by changing the length of the intermediate core portion 33 extending integrally in the first direction Dx. Therefore, it becomes possible to easily change the coupling degree as compared with the case of changing the reactor core 23 itself in order to change the coupling degree.

[0030] In the step-up circuit 100 of this embodiment, since miniaturization can be achieved by providing the magnetic coupling reactor 10, the installation freedom degree of the step-up circuit 100 can be improved.

[0031] <Modification Example of the Embodiment> Next, a modification example of the above-described embodiment will be described with reference to FIG. 5. Since the modification example of this embodiment is only different from the above embodiment in the configuration of the first outer core portion and the second outer core portion, the same reference numerals will be given to the same parts as those in the above embodiment and the description thereof will be made, and redundant descriptions will be omitted.

[0032] As shown in FIG. 5, the magnetically coupled reactor 210 in this modification includes a first coil portion 21, a second coil portion 22, and a reactor core 223. Similar to the reactor core 23 of the above-described embodiment, the reactor core 223 forms a single closed magnetic path that magnetically couples the first coil portion 21 and the second coil portion 22. The first coil portion 21 and the second coil portion 22 are wound around the reactor core 223 so as to cancel each other's magnetic fluxes.

[0033] The reactor core 223 includes a first outer core portion 231, a second outer core portion 232, and two intermediate core portions 33. The first outer core portion 231 includes two first leg portions 235 and one first base portion 36. The two first leg portions 235 both extend in the first direction Dx. The two first leg portions 235 have the same square prism shape and have the same length in the first direction Dx. These two first leg portions 235 are arranged to be spaced apart in the second direction Dy. The interval between the two first leg portions 235 in the second direction Dy is set according to the wire diameter of the first coil portion 21 and the like.

[0034] The first leg portion 235 includes a leg body 235A and a split leg portion 235B. The leg body 235A and the split leg portion 235B are arranged side by side in the first direction Dx. The split leg portion 235B is formed so as to extend the leg body 235A to the second side Dx2 in the first direction Dx and is spaced apart from the leg body 235A in the first direction Dx. In this modification, the end face 235At of the second side Dx2 of the leg body 235A and both end faces 235Bt of the split leg portion 235B in the first direction Dx all extend in a direction intersecting the first direction Dx. The end faces 235At and 235Bt in this modification are formed in parallel planes. Note that the shapes of the end faces 235At and 235Bt only need to extend in a direction intersecting the first direction Dx and are not limited to parallel planes. Also, although the length dimensions of the leg body 235A and the split leg portion 235B in the first direction Dx illustrated in this modification are the same, these length dimensions are not limited to being the same.

[0035] The first base portion 36 has the same configuration as the first base portion 36 of the above-described embodiment, and connects the two first leg portions 235 on the first side Dx1 in the first direction Dx. In other words, the first base portion 36 is disposed on the first side Dx1 in the first direction Dx of the two first leg portions 235, and is formed to extend in the second direction Dy between the two first leg portions 35.

[0036] The second outer core portion 232 is formed symmetrically with the first outer core portion 231 in the first direction Dx. The second outer core portion 232 includes two second leg portions 237 and one second base portion 38. Both of the two second leg portions 237 extend in the first direction Dx. The two second leg portions 237 of the present embodiment have the same quadrangular prism shape as the first leg portion 235. The lengths of the two second leg portions 237 in the first direction Dx are the same. These two second leg portions 237 are spaced apart in the second direction Dy. The interval between the two second leg portions 237 in the second direction Dy is the same as the interval between the two first leg portions 235 in the second direction Dy.

[0037] The second leg portion 237 includes a leg body 237A and a split leg portion 237B. The leg body 237A and the split leg portion 237B are arranged side by side in the first direction Dx. The split leg portion 237B is formed to extend the leg body 237A to the first side Dx1 in the first direction Dx, and is spaced apart from the leg body 237A in the first direction Dx. Similar to the above-described first leg portion 235, in this modification, the end face 237At of the first side Dx1 of the leg body 237A and both end faces 237Bt of the split leg portion 237B in the first direction Dx all extend in a direction intersecting the first direction Dx. The end faces 237At and 237Bt in this modification are formed in parallel planes with each other. Note that the shapes of the end faces 237At and 237Bt only need to extend in a direction intersecting the first direction Dx, and are not limited to parallel planes with each other. Also, although the length dimensions of the leg body 237A and the split leg portion 237B in the first direction Dx illustrated in this modification are the same, these length dimensions are not limited to being the same.

[0038] The second base portion 38 has the same configuration as the second base portion 38 of the above-described embodiment and connects the two second leg portions 37 on the first side Dx1 in the first direction Dx. In other words, the second base portion 38 is disposed on the second side Dx2 in the first direction Dx of the two second leg portions 237 and is formed to extend between the two second leg portions 237 in the second direction Dy.

[0039] Between the leg body 235A and the split leg 235B of the first leg 235 (hereinafter referred to as the third connection portion 43), and between the leg body 237A and the split leg 237B of the second leg 237 (hereinafter referred to as the fourth connection portion 44), second separators 239 are respectively disposed. The second separator 239 has the same configuration as the first separator 39 described above, and for example, a material excellent in heat resistance such as epoxy or alumina can be used. By this second separator 239, the magnetic resistance in the first direction Dx within the first leg 235 and the second leg 237 is increased.

[0040] The second separator 239 (in other words, the third connection portion 43) provided in the first leg 235 is disposed within the range where the first coil portion 21 is wound in the first direction Dx. Similarly, the second separator 239 (in other words, the fourth connection portion 44) provided in the second leg 237 is disposed within the range where the second coil portion 22 is wound in the first direction Dx.

[0041] Here, similar to the above-described embodiment, the first connection portion 41 where the first leg 235 is connected to the intermediate core portion 33 is located within the range where the first coil portion 21 is wound in the first direction Dx. Similarly, the second connection portion 42 where the second leg 37 is connected to the intermediate core portion 33 is located within the range where the second coil portion 22 is wound in the first direction Dx. That is, the first connection portion 41, the second connection portion 42, the third connection portion 43, and the fourth connection portion 44 are all located within the range where the first coil portion 21 or the second coil portion 22 is wound in the first direction Dx, and the first connection portion 41, the second connection portion 42, the third connection portion 43, and the fourth connection portion 44 are covered by the first coil portion 21 or the second coil portion 22.

[0042] In this modified example, the first connecting portion 41 and the third connecting portion 43 are formed at positions symmetric in the first direction Dx with respect to the intermediate portion 21C of the first coil portion 21, and the second connecting portion 42 and the fourth connecting portion 44 are formed at positions symmetric in the first direction Dx with respect to the intermediate portion 22C of the second coil portion 22. More specifically, in this modified example, the first connecting portion 41 and the third connecting portion 43 are respectively located at the boundary positions when the first coil portion 21 is divided into three equal parts in the first direction Dx, and the second connecting portion 42 and the fourth connecting portion 44 are respectively located at the boundary positions when the second coil portion 22 is divided into three equal parts in the first direction Dx are exemplified, but the positions of the first connecting portion 41 to the fourth connecting portion 44 are not limited to the above positions.

[0043] <Function and effect> As described above, in the magnetic coupling type reactor 10 in the modified example of the present embodiment, the second separator 239 that increases the magnetic resistance is provided within the range where the first coil portion 21 is wound around the first leg portion 235 of the first outer core portion 231 and within the range where the second coil portion 22 is wound around the second leg portion 237 of the second outer core portion 232. In this case, since the number of air gaps formed in the reactor core 223 can be increased, it is possible to suppress the occurrence of magnetic saturation. Further, since the first separator 39 and the second separator 239 can be covered by the first coil portion 21 or the second coil portion 22, it is possible to suppress the magnetic flux leaking from the first separator 39 and the second separator 239 from interlinking with the first coil portion 21 and the second coil portion 22, and reduce the eddy current generated in the first coil portion 21 and the second coil portion 22.

[0044] In the above modified example, similar to the above embodiment, the coupling degree between the first coil portion 21 and the second coil portion 22 can be adjusted only by changing the length of the intermediate core portion 33 extending integrally in the first direction Dx. Therefore, it is possible to easily change the coupling degree as compared with the case of changing the reactor core 223 itself in order to change the coupling degree.

[0045] <Other embodiments> Although the embodiments of the present disclosure have been described above, the present disclosure is not limited thereto, and can be modified as appropriate without departing from the technical spirit of the present disclosure. In the above embodiment, an example has been described in which the present disclosure is applied to the boost circuit 100 of a hybrid hydraulic excavator, but it may also be applied to other boost circuits. In the above embodiment, the reactor core 23 is formed by stacking electromagnetic steel sheets. However, the reactor core 23 may be formed by pressing raw material powder containing soft magnetic powder. Examples of the soft magnetic powder contained in the raw material powder include powders of various alloys and pure iron, which are soft magnetic materials.

[0046] In the above embodiment and modified example, the first outer core portion 31 and the second outer core portion 32 are formed by combining quadrangular prism shapes. However, the first outer core portion 31 and the second outer core portion 32 are not limited to the above shapes as long as they are U-shaped when viewed from the third direction Dz. In addition, the intermediate core portion 33 extends linearly in the first direction Dx, but is not limited to a linear shape and may be, for example, a curved shape or a shape that is an appropriate combination of curves and straight lines.

[0047] In the modified example of the above embodiment, a case has been described in which a second separator 239 for increasing magnetic resistance is provided both within the range of the first leg 235 of the first outer core portion 231 where the first coil portion 21 is wound and within the range of the second leg 237 of the second outer core portion 232 where the second coil portion 22 is wound. However, the second separator 239 may be provided in at least one of the range of the first leg 235 of the first outer core portion 231 where the first coil portion 21 is wound and the range of the second leg 237 of the second outer core portion 232 where the second coil portion 22 is wound.

[0048] Furthermore, in the above-described modification, the case where two separators, i.e., the first separator 39 and the second separator 239, are provided within the range where one of the divided coil portions of the first divided coil portions 21A and 21B and the second divided coil portions 22A and 22B is wound has been described. However, three or more separators (in other words, air gaps) may be provided at intervals in the first direction Dx.

[0049] Between the first outer core portions 31 and 231 and the intermediate core portion 33, and between the second outer core portions 32 and 232 and the intermediate core portion 33 in the above-described embodiment and modification, other core portions formed by extending the first leg portions 35 and 235 and the second leg portions 37 and 237 in the first direction Dx may be provided. An insulating material made of, for example, synthetic resin may be appropriately disposed between the first coil portion 21 and the reactor core 23 and between the second coil portion 22 and the reactor core 23 in the above-described embodiment.

Explanation of Reference Numerals

[0050] 10... Magnetic coupling reactor 11A, 11B... Smoothing capacitor 12... Switching element 13... Freewheeling diode 14... Boost chopper circuit 15... High-side arm 16... Low-side arm 21... First coil portion 21A, 21B... First divided coil portion 21C... Intermediate portion 22... Second coil portion 22A, 22B... Second divided coil portion 22C... Intermediate portion 23, 223... Reactor core 31, 231... First outer core portion 32, 232... Second outer core portion 33... Intermediate core portion 33A... First intermediate core portion 33B... Second intermediate core portion 35, 235... First leg portion 35t... End face 36... First base portion 37, 237... Second leg portion 37t... End face 38... Second base portion 39... First separator 41... First connection portion 42... Second connection portion 43... Third connection portion 44... Fourth connection portion 235A... Leg portion main body 235At... End face 235B... Divided leg portion 235Bt... End face 237A... Leg portion main body 237At... End face 237B... Divided leg portion 237Bt... End face 239... Second separator

Claims

1. A reactor core forming a closed magnetic circuit, A first coil part wound in a split manner around the reactor core, A second coil part wound in a split manner around a position of the reactor core spaced apart from the first coil part in a first direction, and comprising: The reactor core includes: A first outer core part having two first leg parts extending in a first direction and a first base part connecting the two first leg parts on a first side in the first direction, A second outer core part having two second leg parts extending in a first direction and a second base part connecting the two second leg parts on a second side in the first direction, Two intermediate core parts arranged side by side in a second direction intersecting the first direction and continuously extending integrally in the first direction to connect the first leg part and the second leg part, And comprising: The first coil part and the second coil part are wound in a split manner so as to at least cross the two intermediate core parts arranged side by side in the second direction, A first connection part connecting the first leg part and the intermediate core part is located within a range where the first coil part is wound in the first direction, A second connection part connecting the second leg part and the intermediate core part is located within a range where the second coil part is wound in the first direction, The first coil part and the second coil part are: Wound in a direction opposite to the direction of the magnetic flux generated in the closed magnetic circuit by the second coil part with respect to the direction of the magnetic flux generated in the closed magnetic circuit by the first coil part, The intermediate core part has no cut extending in a direction intersecting the first direction in the middle of the first direction A magnetic coupling type reactor.

2. At least one of the first connection part and the second connection part has a first separator for increasing magnetic resistance The magnetic coupling type reactor according to claim 1.

3. At least one of the range within which the first coil portion is wound among the first leg portions of the first outer core portion and the range within which the second coil portion is wound among the second leg portions of the second outer core portion has a second separator that increases magnetic resistance. The magnetic coupling type reactor according to claim 1 or 2.

4. The magnetic coupling type reactor according to any one of claims 1 to 3, and A two-phase chopper circuit connected to the first coil portion and the second coil portion of the magnetic coupling type reactor, and Two smoothing capacitors connected between the input terminals and between the output terminals, and A boost circuit comprising the same.

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