Coil, reactor, converter, and power conversion device

Abstract

To provide a reactor that can be miniaturized and yet can measure the coil temperature with high accuracy.SOLUTION: A reactor includes a coil, a magnetic core, and a temperature sensor. The coil includes a first coil portion and a second coil portion. The first coil portion includes a plurality of first turns formed by edgewise winding a rectangular wire. Each of the plurality of first turns includes a first inner circumferential portion constituting the inner circumferential side of the first turn and a first outer circumferential portion constituting the outer circumferential side of the first turn. The first outer circumferential portion is bent so as to incline toward a first direction relative to the first inner circumferential portion. The second coil portion includes a plurality of second turns formed by edgewise winding a rectangular wire. Each of the plurality of second turns has a second inner circumferential portion constituting the inner circumferential side of the second turn and a second outer circumferential portion constituting the outer circumferential side of the second turn. The second outer circumferential portion is bent so as to incline toward a second direction relative to the second inner circumferential portion. The temperature sensor is disposed in a space formed between the first coil portion and the second coil portion.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to a reactor, a converter, and a power conversion device. [Background technology]

[0002] Patent Documents 1 and 2 disclose reactors equipped with a temperature sensor. In the reactor of Patent Document 1, the temperature sensor is attached to the outer circumferential surface of the coil. In the reactor of Patent Document 2, the temperature sensor is provided on a gap plate arranged in the core. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2018-26504 [Patent Document 2] Japanese Patent Application Publication No. 2019-36696 Summary of the Invention [Problem to be solved by the invention]

[0004] In a reactor equipped with a temperature sensor, a structure that allows the reactor to be made smaller is desired, and it is also desired to measure the coil temperature more accurately.

[0005] In the reactor of Patent Document 1, the temperature sensor is disposed on the outer peripheral surface of the coil, which results in a large reactor size including the temperature sensor. When the temperature sensor is disposed inside the gap plate, as in the reactor of Patent Document 2, the thickness of the gap plate depends on the thickness of the temperature sensor. The gap plate must be thicker than the temperature sensor, which results in a thicker gap plate. As the gap plate becomes thicker, the magnetic resistance of the core increases and leakage flux from the portion where the gap plate is disposed increases. With the reactor of Patent Document 2, there is a risk that desired magnetic characteristics may not be achieved.

[0006] An object of the present disclosure is to provide a reactor that can be miniaturized and yet can accurately measure the coil temperature. Another object of the present disclosure is to provide a converter including the reactor and a power conversion device including the converter. [Means for solving the problem]

[0007] A reactor according to the present disclosure includes a coil, a magnetic core in which the coil is disposed, and a temperature sensor that measures the temperature of the coil, the coil having a first coil portion and a second coil portion that is continuously connected to the first coil portion in the axial direction of the coil, the first coil portion having a plurality of first turns formed by spirally wound edgewise from a rectangular wire, each of the plurality of first turns having a first inner peripheral portion that constitutes an inner peripheral side of the first turn of the rectangular wire and a first outer peripheral portion that constitutes an outer peripheral side of the first turn of the rectangular wire, and the first outer peripheral portion is spaced apart from the first inner peripheral portion by a distance of The second coil portion is bent so as to tilt toward a first direction in the axial direction of the coil, and the second coil portion has a plurality of second turns in which the flat wire is wound edgewise in a spiral shape, and each of the plurality of second turns has a second inner peripheral portion that forms the inner side of the second turn in the flat wire and a second outer peripheral portion that forms the outer side of the second turn in the flat wire, and the second outer peripheral portion is bent so as to tilt toward a second direction in the axial direction of the coil relative to the second inner peripheral portion, and the temperature sensor is arranged in the space formed between the first coil portion and the second coil portion.

[0008] The converter of the present disclosure includes the reactor of the present disclosure.

[0009] The power conversion device of the present disclosure includes the converter of the present disclosure. [Effects of the Invention]

[0010] The reactor of the present disclosure can be miniaturized and still measure the coil temperature with high accuracy.

[0011] The converter and the power conversion device of the present disclosure include a reactor that is small and can measure the temperature of the coil with high accuracy. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is a schematic plan view illustrating an example of a reactor according to an embodiment. [Figure 2] FIG. 2 is a schematic exploded plan view illustrating an example of a reactor according to the embodiment. [Figure 3] FIG. 3 is a schematic plan view showing a main part of the reactor according to the embodiment. [Figure 4] FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. [Figure 5] FIG. 5 is a schematic perspective view showing an example of a coil used in the reactor according to the embodiment. [Figure 6] FIG. 6 is a schematic end view of a coil used in the reactor according to the embodiment, as viewed from the axial direction. [Figure 7] FIG. 7 is a cross-sectional view taken along line VII-VII in FIG. [Figure 8] FIG. 8 is a schematic diagram illustrating the configuration of a bending section in a winding machine used to manufacture a coil used in a reactor according to the embodiment. [Figure 9] FIG. 9 is a schematic diagram illustrating the operation of the bending section. [Figure 10] FIG. 10 is another schematic diagram illustrating the operation of the bending section. [Figure 11] FIG. 11 is a schematic diagram for explaining a method for manufacturing a coil. [Figure 12] FIG. 12 is another schematic diagram for explaining the method of manufacturing the coil. [Figure 13] FIG. 13 is a schematic diagram showing the power supply system of a hybrid vehicle. [Figure 14] FIG. 14 is a circuit diagram showing an outline of an example of a power conversion device including a converter. DETAILED DESCRIPTION OF THE INVENTION

[0013] [Description of the embodiments of the present disclosure] First, embodiments of the present disclosure will be listed and described.

[0014] (1) A reactor according to an embodiment of the present disclosure includes a coil, a magnetic core in which the coil is disposed, and a temperature sensor that measures the temperature of the coil. The coil includes a first coil portion and a second coil portion that is continuously connected to the first coil portion in an axial direction of the coil. The first coil portion includes a plurality of first turns of a rectangular wire wound edgewise in a spiral shape. Each of the plurality of first turns has a first inner circumferential portion that constitutes an inner circumferential side of the first turn of the rectangular wire and a first outer circumferential portion that constitutes an outer circumferential side of the first turn of the rectangular wire. The first outer circumferential portion is connected to the first inner circumferential portion. The first coil portion is bent so as to incline toward a first direction in the axial direction of the coil relative to the first coil portion, and the second coil portion has a plurality of second turns in which the flat wire is wound edgewise in a spiral shape, and each of the plurality of second turns has a second inner peripheral portion that forms the inner side of the second turn in the flat wire and a second outer peripheral portion that forms the outer side of the second turn in the flat wire, and the second outer peripheral portion is bent so as to incline toward a second direction in the axial direction of the coil relative to the second inner peripheral portion, and the temperature sensor is arranged in the space formed between the first coil portion and the second coil portion.

[0015] The reactor of the present disclosure can be made smaller because the temperature sensor is disposed in the space formed between the first coil portion and the second coil portion.

[0016] The reactor of the present disclosure can measure the temperature of the coil with high accuracy. By disposing the temperature sensor in the space, the temperature of the coil or the temperature of a location very close to the coil can be measured.

[0017] In the reactor of the present disclosure, a space for disposing a temperature sensor is secured between the first coil portion and the second coil portion. The outer peripheries of the first turn and the second turn are bent so as to be inclined in opposite directions to each other, thereby forming a gap between the first coil portion and the second coil portion large enough to dispose a temperature sensor.

[0018] (2) In one embodiment of the reactor of the present disclosure, the temperature sensor may be fixed to either the first turn or the second turn that face each other.

[0019] In the above embodiment, the temperature sensor is fixed to the coil, so that the temperature of the coil can be measured more accurately.

[0020] (3) In one embodiment of the reactor described in (2) above, the temperature sensor may be located in one of the first inner circumferential portion and the second inner circumferential portion.

[0021] In the above embodiment, the temperature sensor is provided on the inner periphery of the coil where the temperature rise is large, so that the temperature of the coil can be measured more accurately.

[0022] (4) In one embodiment of the reactor of the present disclosure, the magnetic core may have an inner core portion disposed inside the coil and a gap portion provided midway along the length of the inner core portion. The gap portion may be disposed inside the space.

[0023] The above configuration allows for more accurate measurement of the coil temperature. When the magnetic core has a gap, leakage magnetic flux occurs from the gap. Therefore, the coil temperature is likely to rise near the gap due to leakage magnetic flux. The above configuration allows for measurement of the coil temperature near the gap.

[0024] (5) In one embodiment of the reactor of the present disclosure, the magnetic core may have an inner core portion disposed inside the coil, and the inner core portion may include a resin core piece formed of a composite material in which soft magnetic powder is dispersed in a resin. The resin core piece may be disposed inside the space.

[0025] The above-described configuration allows for more accurate measurement of the coil temperature. Resin core pieces have low thermal conductivity and poor heat dissipation. When the inner core portion includes a resin core piece, the resin core piece tends to become hot, and the coil temperature tends to rise in the area where the resin core piece is located. The above-described configuration allows for measurement of the coil temperature in the area where the resin core piece is located.

[0026] (6) In one embodiment of the reactor of the present disclosure, the first turn may have a corner where the rectangular wire is bent, and a first displacement amount in the axial direction of the coil between the first inner circumferential portion and the first outer circumferential portion at the corner of the first turn may be 0.1 mm or more and 1.0 mm or less. The second turn may have a corner where the rectangular wire is bent, and a second displacement amount in the axial direction of the coil between the second inner circumferential portion and the second outer circumferential portion at the corner of the second turn may be 0.1 mm or more and 1.0 mm or less.

[0027] When the first displacement amount of the first turn and the second displacement amount of the second turn are within the above ranges, it is easy to ensure the space in which the temperature sensor is disposed.

[0028] (7) A converter according to an embodiment of the present disclosure includes the reactor according to any one of (1) to (6) above.

[0029] The converter of the present disclosure includes the above reactor, which is small and capable of measuring the coil temperature with high accuracy.

[0030] (8) A power conversion device according to an embodiment of the present disclosure includes the converter described in (7) above.

[0031] The power conversion device of the present disclosure includes the converter, and therefore includes the reactor, which is small and can measure the coil temperature with high accuracy.

[0032] [Details of the embodiments of the present disclosure] Specific examples of the reactor, converter, and power conversion device of the present disclosure will be described with reference to the drawings. In the drawings, the same reference numerals indicate the same or corresponding parts. It should be noted that the present invention is not limited to these examples, but is defined by the scope of the claims, and is intended to include all modifications within the meaning and scope equivalent to the claims.

[0033] <Reactor Overview> An overview of a reactor 100 according to an embodiment will be described mainly with reference to FIGS. 1 to 4. As shown in FIGS. 1 and 2, the reactor 100 includes a coil 10 and a magnetic core 30. The magnetic core 30 is configured in a θ shape as a whole. Furthermore, as shown in FIGS. 3 and 4, the reactor 100 includes a temperature sensor 50. The coil 10 has a first coil portion 110 and a second coil portion 120. One of the features of the reactor 100 is that the temperature sensor 50 is disposed in a space 15 formed between the first coil portion 110 and the second coil portion 120. The configuration of the reactor 100 will be described in detail below.

[0034] 3 and 4 show simplified components of the reactor 100. FIG. 3 shows only the inner core portion 30i of the magnetic core 30, which is disposed inside the coil 10. For convenience, FIG. 3 shows the gap portion 30g with hatching. In this embodiment, the inner core portion 30i is the middle core portion 300 shown in FIGS. 1 and 2. In this embodiment, the side on which the temperature sensor 50 is disposed is the upper side of the reactor. FIG. 4 shows only the upper half of the cross section taken along line IV-IV in FIG. 3. Line IV-IV in FIG. 3 is a line that follows the axial direction of the coil 10.

[0035] (coil) First, an overview of the coil 10 will be described, mainly with reference to FIGS. 5 and 6. The coil 10 is an edgewise coil made of a rectangular wire 1. As shown in FIG. 5, the coil 10 is formed by a plurality of turns 2 in which the rectangular wire 1 is wound edgewise in a spiral shape. Terminal portions 131 and 132 from which the rectangular wire 1 is drawn are provided at both ends of the coil 10. The terminal portion 131 is drawn from a first end 121 of the coil 10. The terminal portion 132 is drawn from a second end 122 of the coil 10. The first end 121 and the second end 122 are formed by turns arranged on both sides of the coil 10. The terminal portions 131 and 132 are portions that protrude outward from the outline of the group of spirally wound turns of the rectangular wire 1. FIG. 5 shows the state of the coil 10 before the terminal portion 132 is flatwise bent in the axial direction of the coil 10 and before it is formed into the shape of the coil 10 shown in FIG. 1. Fig. 6 is a view of the coil 10 shown in Fig. 5 as viewed in the axial direction from the first end portion 121 side. In Fig. 6, the illustration of the terminal portion 132 of the coil 10 is omitted.

[0036] The shape of the coil 10 may be cylindrical or rectangular. A cylindrical shape refers to a coil 10 whose end face is circular when viewed from the axial direction. A circular shape includes not only a perfect circle but also an ellipse. A rectangular cylindrical shape refers to a coil whose end face is polygonal. Examples of polygonal shapes include a triangular shape, a square shape, a hexagonal shape, and an octagonal shape. A rectangular shape includes a rectangular shape and a trapezoidal shape. A rectangular shape includes a square shape. In this embodiment, the coil 10 is rectangular. Specifically, the coil 10 is a rectangular cylindrical coil whose end face is rectangular.

[0037] (Rectangular wire) The flat wire 1 is a winding wire with a rectangular cross section. The cross section is perpendicular to the longitudinal direction of the flat wire 1. The rectangle has a pair of short sides and a pair of long sides, as in the flat wire 1 shown in Figure 8. The width of the flat wire 1 is the distance between the opposing short sides and corresponds to the length of the long sides. The width direction of the flat wire 1 is essentially the direction along the long sides of the rectangle. The thickness of the flat wire 1 is the distance between the opposing long sides and corresponds to the length of the short sides. The thickness direction of the flat wire 1 is essentially the direction along the short sides of the rectangle. The width and thickness of the flat wire 1 can be selected as appropriate. The width of the flat wire 1 is, for example, 3 mm to 15 mm, or even 5 mm to 12 mm. The thickness of the flat wire 1 is, for example, 0.5 mm to 5 mm, or even 0.8 mm to 3 mm.

[0038] (turn) The turns 2 are formed by spirally winding the rectangular wire 1. The shape of each turn 2 is substantially the same as the shape of the end face of the coil 10 described above. The shape of the turn 2 refers to the shape of the turn 2 as viewed from the axial direction. In this embodiment, as shown in FIG. 6, the shape of the turn 2 is rectangular. The turn 2 has four straight portions 20s where the rectangular wire 1 is linearly arranged, and four corner portions 20c where the rectangular wire 1 is bent.

[0039] The number of turns 2 can be appropriately selected, for example, from 10 turns to 60 turns, or from 20 turns to 50 turns.

[0040] (First coil section and second coil section) The configuration of the coil 10 will be described in detail with reference to Figure 7. Figure 7 shows only the cross section taken along the VII-VII line in Figure 6. The configuration visible beyond the cross section is omitted in Figure 7. Line VII-VII in Figure 6 is a diagonal line of the turn 2. The coil 10 has a first coil section 110 and a second coil section 120. The first coil section 110 has a plurality of first turns 21 formed by spirally edgewise winding the rectangular wire 1. The second coil section 120 has a plurality of second turns 22 formed by spirally edgewise winding the rectangular wire 1. One of the features of the coil 10 is that the rectangular wire 1 forming the first turns 21 and the second turns 22 has a specific shape.

[0041] The first coil portion 110 and the second coil portion 120 are arranged coaxially and continuously connected in the axial direction of the coil 10. In other words, the first coil portion 110 and the second coil portion 120 are electrically connected in series and mechanically arranged side by side in the axial direction of the coil 10. The first coil portion 110 and the second coil portion 120 are formed from a single continuous flat wire 1. The first coil portion 110 and the second coil portion 120 are seamlessly formed from a continuous flat wire 1. The axial direction of the first coil portion 110 and the axial direction of the second coil portion 120 coincide with the axial direction of the coil 10.

[0042] First Turn As shown in FIG. 7, the first coil portion 110 is formed by a plurality of first turns 21. The number of first turns 21 can be selected as appropriate. Each of the plurality of first turns 21 has a first inner circumferential portion 11i and a first outer circumferential portion 11e. The first inner circumferential portion 11i constitutes the inner circumferential side of the first turn 21 in the flat wire 1. The first outer circumferential portion 11e constitutes the outer circumferential side of the first turn 21 in the flat wire 1. The first outer circumferential portion 11e is bent so as to incline toward a first direction, which is the axial direction of the coil 10, relative to the first inner circumferential portion 11i. Specifically, the flat wire 1 forming the first turn 21 is bent midway across the width of the flat wire 1. The first inner circumferential portion 11i and the first outer circumferential portion 11e are connected via a bent portion 11b. The first inner circumferential portion 11i is located closer to the inner circumferential side of the first turn 21 than the bent portion 11b in the flat wire 1. The first outer peripheral portion 11e is a portion of the rectangular wire 1 that is located closer to the outer periphery of the first turn 21 than the bent portion 11b. In this embodiment, the rectangular wire 1 in the first turn 21 is bent in the middle of the width direction at both the corners 20c and the straight portions 20s shown in FIG. 6. The bend in the rectangular wire 1 tends to be smaller at the straight portions 20s than at the corners 20c. The reason for this will be explained in the coil manufacturing method described later.

[0043] When viewed in a cross section along the axial direction of the coil 10, the first inner circumferential portion 11i extends substantially along the radial direction from the inner circumferential side to the outer circumferential side of the first turn 21. In other words, the first inner circumferential portion 11i extends substantially parallel to the radial direction of the first turn 21. The first inner circumferential portion 11i is deemed to extend along the radial direction to the extent that it is deviated from the radial direction due to the winding pitch of the rectangular wire 1.

[0044] The first direction is the direction from one end of the coil 10 to the other end in the axial direction. Of both end portions of the coil 10, the end portion on the side where the first coil portion 110 is located is referred to as the first end portion 121, and the end portion on the side where the second coil portion 120 is located is referred to as the second end portion 122. In this embodiment, in FIG. 7, the end portion of the coil 10 located on the lower side is referred to as the first end portion 121, and the end portion of the coil 10 located on the upper side is referred to as the second end portion 122. The first direction is the direction from the first end portion 121 to the second end portion 122. In FIG. 7, the first direction is the direction from bottom to top. In other words, the first outer peripheral portion 11e is inclined upward relative to the first inner peripheral portion 11i.

[0045] The length of the first inner peripheral portion 11i in the width direction of the rectangular wire 1 is, for example, 30% to 75% and even 40% to 70% of the width of the rectangular wire 1. The length of the first outer peripheral portion 11e in the width direction of the rectangular wire 1 is, for example, 25% to 70% and even 30% to 60% of the width of the rectangular wire 1.

[0046] <First displacement amount> A first displacement amount 11d between the first inner peripheral portion 11i and the first outer peripheral portion 11e in the axial direction of the coil 10 is, for example, 0.1 mm or more and 1.0 mm or less, and further, 0.2 mm or more and 0.6 mm or less. The first displacement amount 11d is the displacement amount at a corner portion of the first turn 21. The displacement amount at a straight portion of the first turn 21 may be smaller than the displacement amount at a corner portion. The corner portion is the corner portion 20c shown in FIG. 6. The straight portion is the straight portion 20s shown in FIG. 6.

[0047] The first displacement amounts 11d may all be the same for the multiple first turns 21. The first displacement amounts 11d for some of the multiple first turns 21 may be different from the first displacement amounts 11d for at least some of the remaining first turns 21. For example, the first displacement amount 11d for the first turn 21 located on the second end 122 side of the multiple first turns 21 may be larger than the first displacement amounts 11d for the other first turns 21. The first turn 21 located on the second end 122 side faces the second turn 22 of the second coil portion 120.

[0048] The first displacement amount 11d can be measured, for example, using a laser distance meter as follows: The coil 10 is placed on a horizontal table with its axial direction vertical. The coil 10 is positioned so that the first end 121 is on top and the second end 122 is on the bottom. The distance from a reference position above the coil 10 to the intersection of the top surface and side surface of the first inner circumferential portion 11i is measured. This distance is defined as the first distance. The side surface of the first inner circumferential portion 11i is the inner circumferential surface of the first turn 21, which corresponds to one short side of the rectangle in the cross section of the rectangular wire 1. The distance from the reference position to the intersection of the top surface and side surface of the first outer circumferential portion 11e is measured. This distance is defined as the second distance. The side surface of the first outer circumferential portion 11e is the outer circumferential surface of the first turn 21, which corresponds to the other short side of the rectangle in the cross section of the rectangular wire 1. The difference between the first distance and the second distance is defined as the first displacement amount 11d. Then, the first displacement amount 11d is measured at all corners 20c of the first turn 21. In this embodiment, the first displacement amount 11d is measured at each of the four corners 20c shown in Fig. 6. The average value of the first displacement amounts 11d of all the measured corners is set to the first displacement amount 11d of the first turn 21.

[0049] <Turn 2> As shown in FIG. 7, the second coil portion 120 is formed by a plurality of second turns 22. The number of second turns 22 can be selected as appropriate. The number of second turns 22 may be the same as or different from the number of first turns 21 constituting the first coil portion 110. Each of the plurality of second turns 22 has a second inner circumferential portion 12i and a second outer circumferential portion 12e. The second inner circumferential portion 12i constitutes the inner circumferential side of the second turns 22 in the rectangular wire 1. The second outer circumferential portion 12e constitutes the outer circumferential side of the second turns 22 in the rectangular wire 1. The second outer circumferential portion 12e is bent so as to incline toward a second direction in the axial direction of the first coil portion 110 relative to the second inner circumferential portion 12i. Specifically, similar to the first turn 21 described above, the rectangular wire 1 forming the second turns 22 is bent midway across the width of the rectangular wire 1. The second inner circumferential portion 12i and the second outer circumferential portion 12e are connected via a bent portion 12b. The second inner peripheral portion 12i is a portion located closer to the inner peripheral side of the second turn 22 than the bent portion 12b of the rectangular wire 1. The second outer peripheral portion 12e is a portion located closer to the outer peripheral side of the second turn 22 than the bent portion 11b of the rectangular wire 1. In this embodiment, the rectangular wire 1 is bent in the middle of the width direction at both the corner portion 20c and the straight portion 20s shown in FIG. 6. The bend of the rectangular wire 1 tends to be smaller at the straight portion 20s than at the corner portion 20c.

[0050] When viewed in a cross section along the axial direction of the coil 10, the second inner circumferential portion 12i extends substantially along the radial direction from the inner circumferential side to the outer circumferential side of the second turn 22. In other words, the second inner circumferential portion 12i extends substantially parallel to the radial direction of the second turn 22. The second inner circumferential portion 12i is considered to be aligned along the radial direction to the extent that it is deviated from the radial direction due to the winding pitch of the rectangular wire 1.

[0051] The second direction is the direction from the other end to one end in the axial direction of the coil 10. The second direction is opposite to the first direction. That is, the second direction is the direction from the second end 122 to the first end 121. In FIG. 7, the second direction is the direction from top to bottom. That is, the second outer peripheral portion 12e is inclined downward with respect to the second inner peripheral portion 12i.

[0052] The length of the second inner peripheral portion 12i in the width direction of the rectangular wire 1 is, for example, 30% to 75% of the width of the rectangular wire 1, and further 40% to 70%. The length of the second outer peripheral portion 12e in the width direction of the rectangular wire 1 is, for example, 25% to 70% of the width of the rectangular wire 1, and further 30% to 60%.

[0053] <Second displacement amount> A second displacement amount 12d between the second inner peripheral portion 12i and the second outer peripheral portion 12e in the axial direction of the coil 10 is, for example, 0.1 mm or more and 1.0 mm or less, and further, 0.2 mm or more and 0.6 mm or less. The second displacement amount 12d is the displacement amount at a corner portion of the second turn 22. The displacement amount at a straight portion of the second turn 22 may be smaller than the displacement amount at the corner portion. The corner portion is the corner portion 20c shown in FIG. 6. The straight portion is the straight portion 20s shown in FIG. 6.

[0054] The second displacement amounts 12d may all be the same for the multiple second turns 22. The second displacement amounts 12d for some of the multiple second turns 22 may be different from the second displacement amounts 12d for at least some of the remaining second turns 22. For example, the second displacement amount 12d for the second turn 22 located on the first end 121 side of the multiple second turns 22 may be larger than the second displacement amounts 12d for the other second turns 22. The second turn 22 located on the first end 121 side faces the first turn 21 of the first coil portion 110.

[0055] The second displacement amount 12d may be measured in the same manner as the first displacement amount 11d described above. The second displacement amount 12d is measured by placing the coil 10 on a horizontal table with the first end 121 facing upward. A first distance from a reference position above the coil 10 to the intersection of the top surface and side surface of the second inner circumferential portion 12i and a second distance to the intersection of the top surface and side surface of the second outer circumferential portion 12e are measured. The difference between the first distance and the second distance is defined as the second displacement amount 12d. The second displacement amounts 12d at all corners of the second turn 22 are then measured, and the average value is defined as the second displacement amount 12d for that second turn 22.

[0056] (space) As shown in FIGS. 3 and 4 , the coil 10 has a space 15 formed between the first coil portion 110 and the second coil portion 120. A temperature sensor 50 is disposed in the space 15. As described above with reference to FIG. 7 , in the first turn 21 constituting the first coil portion 110, the first outer peripheral portion 11e is bent so as to be inclined in a first direction relative to the first inner peripheral portion 11i. In the second turn 22 constituting the second coil portion 120, the second outer peripheral portion 12e is bent so as to be inclined in a second direction relative to the second inner peripheral portion 12i. Because the first turn 21 and the second turn 22 are bent in opposite directions, the first turn 21 and the second turn 22 facing each other are spaced apart. This forms a space 15 between the first coil portion 110 and the second coil portion 120. In this embodiment, as described above, the rectangular wire 1 is bent midway in the width direction at each corner 20c of the first turn 21 and the second turn 22. Therefore, the space 15 is formed between the straight portions 20s of the first turn 21 and the second turn 22.

[0057] The spacing of the space 15 is, for example, 0.2 mm or more and 2.0 mm or less. When the spacing of the space 15 is 0.2 mm or more, the space 15 can be easily used as a storage space for the temperature sensor 50. When the spacing of the space 15 is 0.5 mm or more, the space 15 can be more easily used as a storage space for the temperature sensor 50. When the spacing of the space 15 is 2.0 mm or less, exposure of the inner core portion 30i arranged inside the coil 10 from the space 15 can be reduced. When the spacing of the space 15 is 1.0 mm or less, the exposed portion of the inner core portion 30i can be further reduced. The spacing of the space 15 is preferably 0.4 mm or more and 1.2 mm or less, or 0.5 mm or more and 1.0 mm or less. The spacing of the space 15 is the distance between the first turn 21 and the second turn 22 facing each other. The spacing of the space 15 is the distance along the axial direction of the coil 10 and is the maximum value of the gap between the first turn 21 and the second turn 22 facing each other.

[0058] The size of the space 15 is determined by the first displacement amount 11d of the first turn 21 and the second displacement amount 12d of the second turn 22. The larger the first displacement amount 11d and the second displacement amount 12d, the larger the size of the space 15. Having the first displacement amount 11d and the second displacement amount 12d be 0.1 mm or greater makes it easier to secure the space 15 in which the temperature sensor 50 is disposed. In particular, for the first turn 21 and the second turn 22 facing each other, the sum of the first displacement amount 11d and the second displacement amount 12d is preferably 0.4 mm or greater and 1.2 mm or less, and even more preferably 0.5 mm or greater and 1.0 mm or less. From the viewpoint of manufacturing the coil 10, the upper limit of each of the first displacement amount 11d and the second displacement amount 12d is preferably 1.0 mm. Furthermore, if the first displacement amount 11d and the second displacement amount 12d are 1.0 mm or less, it is difficult to see at a glance that the rectangular wire 1 is bent midway in the width direction. In other words, it is easy to obtain a coil with a good appearance comparable to conventional coils.

[0059] In this embodiment, a gap 30g is provided in the inner core portion 30i. The space 15 is located outside the gap 30g. Therefore, the temperature sensor 50 is provided outside the gap 30g.

[0060] <Gaps between turns> Furthermore, as shown in FIG. 7, in the first coil portion 110, the flat wire 1 forming the first turn 21 is bent midway in the width direction, thereby reducing the gap 21g between the first turns 21. In the second coil portion 120, the flat wire 1 forming the second turn 22 is bent midway in the width direction, thereby reducing the gap 22g between the second turns 22. The reason why the gaps 21g and 22g are reduced is unclear, but it is thought to be as follows: It is presumed that the bending of the flat wire 1 midway in the width direction applies a pulling force to each of the first turn 21 and the second turn 22 in the direction in which the flat wire 1 is bent, thereby narrowing the distance between the first turns 21 and the second turns 22. When the first displacement 11d of the first turn 21 and the second displacement 12d of the second turn 22 are 0.1 mm or more, the effect of reducing the gaps 21g and 22g is easily achieved.

[0061] The gaps 21g and 22g are, for example, 0.076 mm or less, further 0.06 mm or less, or 0.05 mm or less. Since the smaller the gaps 21g and 22g are, the better, no lower limit is set. In other words, the lower limit is zero.

[0062] The gap 21g between the first turns 21 can be calculated as the average value of all the gaps 21g. The gap 21g is calculated as [(L1-n1×t) / (n1-1)], where L1 is the length (mm) of the first coil portion 110, n1 is the number of turns of the first turn 21, and t is the thickness (mm) of the rectangular wire 1.

[0063] The length L1 of the first coil portion 110 is measured as follows: A line parallel to the axial direction of the coil 10 is drawn at any position in the circumferential direction of the outer circumferential surface of the first coil portion 110. This line is an imaginary line tangent to the outer circumferential surface of the first turn 21. Of the first turns 21 on the line, the linear distance between the first turns 21 located at both ends is determined. This distance is defined as the length L1. The length L1 of the first coil portion 110 is preferably measured by placing the coil 10 on a horizontal table so that the axial direction of the coil 10 is horizontal. The measurement is performed with no load applied to the coil 10. The number of turns n1 of the first turns 21 is defined as the number of first turns 21 that intersect with the line. (n1-1) represents the number of gaps 21g between the first turns 21.

[0064] The gap 22g between the second turns 22 may be measured in the same manner as the gap 21g between the first turns 21 described above. The gap 22g is calculated as [(L2-n2×t) / (n2-1)], where L2 is the length (mm) of the second coil portion 120. n2 is the number of turns of the second turn 22.

[0065] The length L2 of the second coil portion 120 can be determined, similarly to the length L1 of the first coil portion 110 described above, by drawing an imaginary straight line parallel to the axial direction of the coil 10 on the outer circumferential surface of the second coil portion 120 and using this straight line. The number of turns n2 of the second turn 22 is the number of second turns 22 that intersect with the above straight line. (n2-1) represents the number of gaps 22g between the second turns 22. The total length L of the coil 10 is the sum of the length L1 of the first coil portion 110 and the length L2 of the second coil portion 120.

[0066] (Temperature sensor) As shown in FIGS. 3 and 4, the temperature sensor 50 is disposed in the space 15 formed between the first coil portion 110 and the second coil portion 120. The temperature sensor 50 measures the temperature of the coil 10. For example, a thermistor, a thermocouple, or a measuring resistor can be used as the temperature sensor 50. The thickness of the temperature sensor 50 is smaller than the distance of the space 15. In FIG. 4, the cross-sectional shapes of the first turn 21 and the second turn 22 are simplified for convenience in explaining the positional relationship between the temperature sensor 50 and the gap portion 30g. In reality, the outer peripheries of the first turn 21 and the second turn 22 are bent so that they approach each other, as shown in FIG. 7.

[0067] The location of the temperature sensor 50 is not particularly limited. In this embodiment, the temperature sensor 50 is located on the upper surface of the coil 10. However, it is preferable to provide the temperature sensor 50 on the side opposite to the installation surface of the reactor 100. The reactor 100 is generally installed on a cooling plate through which a refrigerant flows. In this embodiment, the lower surface of the reactor 100 is the installation surface that is placed on the cooling plate. In this case, the lower surface of the coil 10 is likely to dissipate heat toward the cooling plate. By providing the temperature sensor 50 on the upper surface of the coil 10, away from the lower surface that is the installation surface, the temperature of the hottest part of the coil 10 can be accurately measured.

[0068] By disposing the temperature sensor 50 in the space 15, the temperature of the coil 10 can be measured with high accuracy. The temperature of the coil 10 is more likely to rise on the inner circumferential surface side of the coil 10 than on the outer circumferential surface side of the coil 10. This is because heat is less likely to escape from the inner circumferential side of the coil 10 where the magnetic core 30 is disposed. In addition, heat generated in the magnetic core 30 is transferred to the coil 10. When the temperature sensor 50 is disposed in the space 15, it is possible to measure the temperature of the part that is most likely to heat up, that is, the part close to the inner circumferential surface side of the coil 10.

[0069] The temperature sensor 50 is preferably fixed to either the first turn 21 or the second turn 22, which face each other. In this embodiment, the temperature sensor 50 is fixed to the first turn 21 by a fixing material 70. Fixing the temperature sensor 50 to either the first turn 21 or the second turn 22 allows for more accurate measurement of the temperature of the coil 10. Examples of the fixing material 70 include adhesive, adhesive tape, and solder.

[0070] Furthermore, the temperature sensor 50 is preferably located on the inner circumferential side of the coil 10, as shown in Fig. 4. Specifically, it is preferable that the temperature sensor 50 be located on one of the first inner circumferential portion 11i and the second inner circumferential portion 12i of the first turn 21 and the second turn 22 shown in Fig. 7. In this embodiment, the temperature sensor 50 is located on the inner circumferential side of the first turn 21, i.e., the first inner circumferential portion 11i. As described above, the temperature rise is large on the inner circumferential side of the coil 10. By locating the temperature sensor 50 on the inner circumferential side of the coil 10, the temperature of the coil 10 can be measured more accurately.

[0071] In this embodiment, the space 15 is located outside the gap portion 30g provided in the inner core portion 30i. Therefore, the temperature sensor 50 is provided outside the gap portion 30g. Leakage magnetic flux occurs in the gap portion 30g. Eddy current loss occurs in the coil 10 due to the leakage magnetic flux near the gap portion 30g, which makes it easy for the temperature of the coil 10 to rise. By providing the temperature sensor 50 outside the gap portion 30g, it is possible to measure the temperature of the coil 10 near the gap portion 30g, where the temperature is highest. This allows for more accurate measurement of the temperature of the coil 10.

[0072] The temperature sensor 50 can be attached to the coil 10 via a fastener 70, for example.

[0073] (magnetic core) The configuration of the magnetic core 30 will be described with reference to Figures 1 and 2. The magnetic core 30 is an assembly of a first core 31 and a second core 32. The first core 31 and the second core 32 will be described later. The magnetic core 30 has a middle core portion 300, a first end core portion 310, a second end core portion 320, a first side core portion 330, and a second side core portion 340.

[0074] (Middle core part) The middle core portion 300 is a portion of the magnetic core 30 that is disposed inside the coil 10. In other words, the middle core portion 300 corresponds to the inner core portion 30i. In this embodiment, the middle core portion 300 is divided into two portions in the longitudinal direction of the middle core portion 300, and includes a first middle core portion 301 and a second middle core portion 302. A gap portion 30g is provided midway along the longitudinal direction of the middle core portion 300. The gap portion 30g is disposed between the first middle core portion 301 and the second middle core portion 302. The gap portion 30g may be an air gap or a plate made of a non-magnetic material such as resin or ceramics. The gap portion 30g may not be provided.

[0075] (First end core part and second end core part) The first end core portion 310 is a portion of the magnetic core 30 that faces the first end 121 of the coil 10. The second end core portion 320 is a portion that faces the second end 122 of the coil 10. The first end core portion 310 and the second end core portion 320 are arranged with a gap between them so as to sandwich the coil 10 in the axial direction.

[0076] (First side core part and second side core part) The first side core portion 330 and the second side core portion 340 are portions of the magnetic core 30 that are arranged outside the coil 10 so as to sandwich the middle core portion 300. The first side core portion 330 and the second side core portion 340 are arranged at a distance from each other so as to sandwich both side surfaces along the axial direction of the coil 10. The first side core portion 330 and the second side core portion 340 have a length that connects the first end core portion 310 and the second end core portion 320.

[0077] (First core, second core) The magnetic core 30 is configured by combining a first core 31 and a second core 32. The shapes of the first core 31 and the second core 32 can be selected from various combinations. In this embodiment, the magnetic core 30 is an ET type that combines an E-shaped first core 31 with a T-shaped second core 32. Other combinations include, for example, an EU type, an EI type, and a TU type.

[0078] In this embodiment, the first core 31 includes a first end core portion 310, a first middle core portion 301 which is a part of the middle core portion 300, and the entire first side core portion 330 and the entire second side core portion 340. The first end core portion 310, the first middle core portion 301, the first side core portion 330, and the second side core portion 340 are integrally formed. The second core 32 includes a second end core portion 320 and a second middle core portion 302 which is the remaining portion of the middle core portion 300. The second end core portion 320 and the second middle core portion 302 are integrally formed.

[0079] The magnetic core 30 is made of, for example, a powder compact or a composite material compact. The powder compact is formed by compressing and molding powder made of a soft magnetic material. Examples of soft magnetic materials include metals such as iron and iron alloys, and non-metals such as ferrite. Examples of iron alloys include Fe-Si alloys and Fe-Ni alloys. Hereinafter, powder made of a soft magnetic material will be referred to as "soft magnetic powder." The content of the soft magnetic powder in the powder compact is, for example, 85% by volume or more and 99.99% by volume or less, when the powder compact is taken as 100% by volume.

[0080] A composite material compact is formed by dispersing soft magnetic powder in resin. A composite material compact is obtained by filling a mold with raw material in which soft magnetic powder is mixed and dispersed in unsolidified resin, and then solidifying the resin. The content of the soft magnetic powder in the composite material is, for example, 20% by volume or more and 80% by volume or less, assuming the composite material to be 100% by volume. Examples of the resin in the composite material include thermosetting resins and thermoplastic resins. Examples of thermosetting resins include epoxy resins, phenolic resins, silicone resins, and urethane resins. Examples of thermoplastic resins include polyphenylene sulfide resins, polyamide resins, polyimide resins, liquid crystal polymers, and fluororesins. Generally, a composite material compact contains more resin than a powder compact, and therefore has lower thermal conductivity than a powder compact. Hereinafter, a core piece made of a composite material compact will be referred to as a "resin core piece."

[0081] The constituent materials of the first core 31 and the second core 32 may be the same or different. For example, the first core 31 and the second core 32 may be composed of powder compacts, or the first core 31 and the second core 32 may be composed of resin core pieces. Alternatively, one of the first core 31 and the second core 32 may be composed of a powder compact and the other may be composed of a resin core piece. In this embodiment, the first core 31 is a resin core piece made of a composite material molded body, and the second core 32 is a powder compact. That is, of the middle core portion 300, the first middle core portion 301 is composed of a resin core piece, and the second middle core portion 302 is composed of a powder compact.

[0082] (holding member) Furthermore, this embodiment has two holding members 41, 42. The holding member 41 is arranged on the first end 121 side of the coil 10. The holding member 42 is arranged on the second end 122 side of the coil 10. The holding members 41, 42 ensure electrical insulation between the coil 10 and the first end core portion 310 and second end core portion 320 of the magnetic core 30. The holding members 41, 42 have through holes 43 formed therein, into which the respective ends of the middle core portion 300 are inserted.

[0083] The holding members 41 and 42 are rectangular frame-shaped. The holding member 41 contacts the turns that make up the first end 121. The terminal portion 131 is drawn out from the holding member 41 in a direction perpendicular to the axial direction of the coil 10. The holding member 42 contacts the turns that make up the second end 122. The holding member 42 has a slit that penetrates the terminal portion 132. The terminal portion 132 passes through the slit and is drawn out in the axial direction of the coil 10.

[0084] (Coil manufacturing method) A method for manufacturing the above-mentioned coil 10 will be described with reference mainly to Figures 8 to 12. The coil 10 can be manufactured using a winding machine. Any known winding machine can be used as the winding machine.

[0085] (winding machine) The winding machine includes a bending section 800 shown in Fig. 8 and a feeding mechanism (not shown). The bending section 800 edgewise bends the rectangular wire 1. The feeding mechanism feeds out the rectangular wire 1. The bending section 800 is one of the main parts of the winding machine.

[0086] (Bent section) As shown in Figures 8 and 9, the bending section 800 has a holding section 810 and a guide section 820. The holding section 810 holds the inner peripheral section 1i of the flat wire 1. The inner peripheral section 1i of the flat wire 1 is the portion located on the inner peripheral side of the bend in the flat wire 1 when the flat wire 1 is bent edgewise. The guide section 820 holds the outer peripheral section 1e of the flat wire 1. The outer peripheral section 1e of the flat wire 1 is the portion located on the outer peripheral side of the bend in the flat wire 1.

[0087] <Holding part> The holding part 810 has a shaft 811 and a support 812 that supports the shaft 811. The shaft 811 is a columnar member that contacts the side surface of the inner peripheral part 1i of the rectangular wire 1. The side surface of the inner peripheral part 1i is a surface that corresponds to one short side of the rectangle in the cross section of the rectangular wire 1. The support 812 is cylindrical. The shaft 811 passes through the center of the support 812. The shaft 811 is slidable in the axial direction of the shaft 811 relative to the support 812. The tip of the shaft 811 protrudes from the end face of the support 812. The tip of the shaft 811 has a disk-shaped flange 813. The support 812 and the flange 813 are arranged at a distance from each other.

[0088] The holding portion 810 has a first surface 812f formed by the end face of the support body 812 and a second surface 813f formed by the surface of the flange 813 facing the support body 812. The first surface 812f and the second surface 813f are arranged opposite each other so as to sandwich the inner peripheral portion 1i of the flat wire 1 in the thickness direction. The inner peripheral portion 1i of the flat wire 1 is passed through and held between the first surface 812f and the second surface 813f. A slight clearance is provided between the first surface 812f and the inner peripheral portion 1i, and between the second surface 813f and the inner peripheral portion 1i, so that the flat wire 1 can pass through when it is fed out.

[0089] <Guide section> The guide part 820 is rotatable around the central axis of the shaft 811. The guide part 820 has a guide groove 821 formed therein so as to sandwich the outer periphery 1e of the flat wire 1 in the thickness direction. The outer periphery 1e of the flat wire 1 is passed through and held in this guide groove 821. The width of the guide groove 821 is slightly larger than the thickness of the outer periphery 1e of the flat wire 1 so that the flat wire 1 can pass through when it is fed out.

[0090] In this embodiment, the guide portion 820 is slidable in the axial direction of the shaft 811 relative to the holding portion 810. The position of the guide portion 820 is controlled by, for example, a driving device (not shown). For example, a servo motor or the like can be used as the driving device.

[0091] The operation of the bending unit 800 when edgewise bending the rectangular wire 1 will be described with reference to Figures 9 and 10. Here, the rectangular coil 10 shown in Figures 5 and 6 will be described as an example. Figures 9 and 10 show the bending unit 800 viewed from the flange 813 side, i.e., from the bottom of Figure 8, in the axial direction of the shaft 811. As shown in Figure 9, the rectangular wire 1 is fed linearly by a feeding mechanism (not shown). The arrow in Figure 9 indicates the feeding direction of the rectangular wire 1. Next, as shown in Figure 10, the guide unit 820 rotates around the central axis of the shaft 811. The side of the inner peripheral portion 1i is pressed against the outer peripheral surface of the shaft 811, and the rectangular wire 1 bends along the outer peripheral surface of the shaft 811. This forms a corner where the rectangular wire 1 is bent edgewise. In this embodiment, the guide unit 820 rotates 90° to bend the rectangular wire 1 90°. By repeating this operation, one turn 2 is formed. The feeding of the rectangular wire 1 and the edgewise bending process are repeated four times to form a rectangular turn 2. Then, the formation of the turn 2 is repeated multiple times to form a plurality of turns 2, thereby forming the coil 10.

[0092] When the flat wire 1 is fed, as shown in Figure 8, the support 812 and the flange 813 are held at a distance such that a gap is formed between them and the inner peripheral portion 1i of the flat wire 1. When the flat wire 1 is edgewise bent, the support 812 and the flange 813 are closed at a distance such that the inner peripheral portion 1i of the flat wire 1 is sandwiched from above and below. When the flat wire 1 is edgewise bent, the inner peripheral side of the bend is deformed so that it bulges in the thickness direction, and the inner peripheral portion 1i becomes thicker. By sandwiching the inner peripheral portion 1i of the flat wire 1 from the thickness direction of the flat wire 1 between the support 812 and the flange 813, it is possible to prevent the inner peripheral portion 1i of the flat wire 1 from becoming thicker during edgewise bending.

[0093] Generally, when a coil is produced using a winding machine, the positional relationship between the holding part 810 and the guide part 820 is set so that the position holding the inner peripheral portion 1i of the flat wire 1 and the position holding the outer peripheral portion 1e of the flat wire 1 are approximately the same in the axial direction of the shaft 811, as shown in Figure 8. In other words, the guide part 820 is positioned relative to the holding part 810 so that the inner peripheral portion 1i and the outer peripheral portion 1e of the flat wire 1 are flat. The position of the guide part 820 at this time is defined as the reference position of the guide part 820. The reference position is the position where the center line between the first surface 812f and the second surface 813f when the holding part 810 holds the inner peripheral portion 1i of the flat wire 1 is aligned with the center line of the width of the guide groove 821 of the guide part 820.

[0094] The method for manufacturing the coil 10 described above will be described in detail with reference to Figures 11 and 12. The method for manufacturing the coil 10 uses a winding machine equipped with the bending processing unit 800 described above. The method for manufacturing the coil 10 includes a step of forming a first turn and a step of forming a second turn. Each step will be described in detail below. In the following description, reference may be made to Figure 7. In this embodiment, winding begins from the first end 121 side of the coil 10.

[0095] (First turn forming process) The process of forming the first turn 21 is performed with the guide portion 820 displaced relative to the holding portion 810 in a first direction, the axial direction of the shaft 811, as shown in FIG. 11 . Specifically, the guide portion 820 is slid upward relative to the holding portion 810, thereby displacing the guide portion 820 upward relative to the holding portion 810. In other words, the first direction is a bottom-to-top direction in FIG. 11 . By displacing the guide portion 820 upward relative to the holding portion 810 in this manner, the rectangular wire 1 is bent so that the outer peripheral portion 1e of the rectangular wire 1 is inclined upward relative to the inner peripheral portion 1i. By forming the first turn 21 in this state, the first turn 21 can be formed, with the first outer peripheral portion 11e inclined upward relative to the first inner peripheral portion 11i, as shown in FIG. 7 . By forming a predetermined number of first turns 21, the first coil portion 110 is formed.

[0096] (Second turn forming process) The process of forming the second turn 22 is performed with the guide portion 820 displaced relative to the holding portion 810 in a second direction, the axial direction of the shaft 811, as shown in FIG. 12 . This second direction is opposite to the first direction used in the process of forming the first turn 21. Specifically, the guide portion 820 is slid downward relative to the holding portion 810, thereby displacing the guide portion 820 downward relative to the holding portion 810. In other words, the second direction is the direction from top to bottom in FIG. 12 . By displacing the guide portion 820 downward relative to the holding portion 810 in this manner, the rectangular wire 1 is bent so that the outer periphery 1e of the rectangular wire 1 is inclined downward relative to the inner periphery 1i. By forming the second turn 22 in this state, the second turn 22 can be formed with the second outer periphery 12e inclined downward relative to the second inner periphery 12i, as shown in FIG. 7 . By forming a predetermined number of second turns 22, the second coil portion 120 is formed.

[0097] By continuously carrying out the process of forming the second turn after the process of forming the first turn, it is possible to manufacture a coil 10 in which the first coil portion 110 and the second coil portion 120 are continuously connected in the axial direction of the coil 10. When the rectangular wire 1 is bent midway in the width direction by displacing the guide portion 820 relative to the holding portion 810, it is possible to reduce the gaps between the first turns 21 and the second turns 22.

[0098] In both the first turn forming process and the second turn forming process, the guide portion 820 is maintained in a displaced state while the first turn 21 and the second turn 22 are formed. In other words, the positional relationship between the holding portion 810 and the guide portion 820 is maintained. During edgewise bending, the inner peripheral portion 1i of the rectangular wire 1 is sandwiched between the support 812 and the flange 813, so that the rectangular wire 1 is bent at the corners of the turn. On the other hand, when the rectangular wire 1 is fed out, the support 812 and the flange 813 are held at a distance such that a gap is formed between them and the inner peripheral portion 1i of the rectangular wire 1. Therefore, it is thought that the bending force is less likely to be applied to the rectangular wire 1 at the straight portions of the turn than at the corners, and the bending of the rectangular wire 1 may be smaller.

[0099] The displacement Gd of the guide portion 820 relative to the holding portion 810 is, for example, 0.1 mm or more and 1.0 mm or less, and more preferably 0.2 mm or more and 0.6 mm or less. The displacement Gd of the guide portion 820 is the distance by which the guide portion 820 is slid in the axial direction of the shaft 811 from the reference position described above. In the first turn formation process, the displacement Gd is the displacement in the first direction, i.e., upward. In the second turn formation process, the displacement Gd is the displacement in the second direction, i.e., downward.

[0100] The width of the inner peripheral portion 1i of the flat wire 1 held by the holding portion 810 is, for example, 30% to 75% of the width of the flat wire 1, and further 40% to 70%. The width of the outer peripheral portion 1e of the flat wire 1 held by the guide portion 820 is, for example, 25% to 70% of the width of the flat wire 1, and further 30% to 60%.

[0101] {Effects of the embodiment} The reactor 100 of the above-described embodiment can be miniaturized. The temperature sensor 50 is disposed in the space 15 formed between the first coil portion 110 and the second coil portion 120. By disposing the temperature sensor 50 inside the outer circumferential surface of the coil 10, it is possible to avoid increasing the size of the reactor 100. Furthermore, the reactor 100 can accurately measure the temperature of the coil 10. The temperature rise is large on the inner circumferential side of the coil 10. By disposing the temperature sensor 50 in the space 15, it is possible to measure the temperature of the portion of the coil 10 close to the inner circumferential surface side. By measuring the temperature on the inner circumferential side of the coil 10, which is most likely to heat up, it is possible to accurately measure the temperature of the coil 10.

[0102] Since the temperature of the coil 10 can be accurately measured, when controlling the energization of the coil 10 based on the temperature of the coil 10, the responsiveness to the temperature change of the coil 10 is improved.

[0103] The coil 10 makes it easy to secure a space 15 in which the temperature sensor 50 can be placed between the first coil portion 110 and the second coil portion 120. The rectangular wire 1 is bent midway in the width direction in the first turn 21 that constitutes the first coil portion 110 and the second turn 22 that constitutes the second coil portion 120. By bending the rectangular wire 1 in opposite directions in the first turn 21 and the second turn 22, it is possible to form a space 15 between the first coil portion 110 and the second coil portion 120 in which the temperature sensor 50 can be placed.

[0104] [Variations] In the above-described embodiment, as described with reference to FIG. 4, the space 15 is located outside the gap portion 30g of the inner core portion 30i. If the inner core portion 30i includes a resin core piece, the space 15 may be located outside the resin core piece. In this case, the temperature sensor 50 is provided outside the resin core piece. In FIG. 4, if the first middle core portion 301 of the middle core portion 300, which is the inner core portion 30i, is a resin core piece, the space 15 is provided outside the first middle core portion 301. Resin core pieces have low thermal conductivity and tend to become hot. Therefore, the temperature of the coil 10 tends to rise in the area where the first middle core portion 301 is located. If the gap portion 30g is not provided, the temperature sensor 50 is provided outside the first middle core portion 301, thereby enabling measurement of the temperature of the coil 10 in the area where the first middle core portion 301 is located, which tends to become hot.

[0105] [Prototype 1] The coil 10 was manufactured by the coil manufacturing method described in the embodiment.

[0106] The specifications of the manufactured coil 10 were as follows: The shape of the coil 10 was a square tube. The shape of the end face of the coil 10 was rectangular. The number of first turns 21 was 16 turns, and the number of second turns 22 was 16 turns.

[0107] The width of the inner peripheral portion 1i of the rectangular wire 1 held by the holding portion 810 was set to about 60% of the width of the rectangular wire 1. The width of the outer peripheral portion 1e of the rectangular wire 1 held by the guide portion 820 was set to about 30% of the width of the rectangular wire 1. The displacement Gd of the guide portion 820 in the process of forming the first turn 21 and the process of forming the second turn 22 was set to 0.2 mm.

[0108] For the manufactured coil 10, the first displacement amount 11d of the first turn 21 and the second displacement amount 12d of the second turn 22 were measured. The measurement of each displacement amount was performed using the measurement method described in the embodiment. Then, for the first displacement amount 11d and the second displacement amount 12d, the displacement amounts at each of the four corner portions 20c were measured and the average value was calculated. As a result, the average displacement amounts at each of the corner portions 20c of the first turn 21 and the second turn 22 were approximately 0.2 mm. Furthermore, the displacement amounts at each of the midpoints of the four straight portions 20s were measured and the average value was calculated. Specifically, the midpoints of the straight portions 20s were defined as the midpoints of the lengths of the straight portions 20s along the circumferential direction of the first turn 21. As a result, the average displacement amounts at each of the straight portions 20s of the first turn 21 and the second turn 22 were approximately 0.1 mm.

[0109] The reason why the amount of displacement at the straight portion 20s is smaller than that at the corner portion 20c is thought to be as follows. During edgewise bending, the inner peripheral portion 1i of the rectangular wire 1 is sandwiched between the support 812 and the flange 813, so the inner peripheral portion 1i is fixed. Therefore, the rectangular wire 1 is easily bent at the corner portion 20c. In contrast, at the straight portion 20s, the support 812 and the flange 813 are held at a distance that forms a gap between them and the inner peripheral portion 1i, so the force that bends the rectangular wire 1 is less likely to be applied compared to the corner portion 20c. It is thought that this relationship between the rectangular wire 1 and the holding portion 810 and the guide portion 820 causes the amount of displacement at the straight portion 20s to be smaller than that at the corner portion 20c.

[0110] Furthermore, the width of the space 15 formed between the first coil portion 110 and the second coil portion 120 was measured, and the result was that the width of the space 15 was about 0.4 mm.

[0111] <Converter / power conversion device> The reactor 100 of the embodiment can be used in applications that satisfy the following energization conditions. Examples of the energization conditions include a maximum DC current of approximately 100 A to 1000 A, an average voltage of approximately 100 V to 1000 V, and an operating frequency of approximately 5 kHz to 100 kHz. The reactor 100 of the embodiment can be used as a component of a converter mounted on a vehicle such as an electric vehicle or a hybrid vehicle, or as a component of a power conversion device equipped with this converter.

[0112] As shown in Fig. 13, a vehicle 1200 such as a hybrid vehicle or an electric vehicle includes a main battery 1210, a power conversion device 1100 connected to the main battery 1210, and a motor 1220 that is driven by power supplied from the main battery 1210 and used for traveling. The motor 1220 is typically a three-phase AC motor that drives wheels 1250 when traveling and functions as a generator during regeneration. In the case of a hybrid vehicle, the vehicle 1200 includes an engine 1300 in addition to the motor 1220. Although Fig. 13 shows an inlet as a charging point for the vehicle 1200, a plug may also be provided.

[0113] The power conversion device 1100 includes a converter 1110 connected to a main battery 1210, and an inverter 1120 connected to the converter 1110 and performing mutual conversion between direct current and alternating current. The converter 1110 shown in this example boosts the input voltage of the main battery 1210, which is approximately 200 V or more and 300 V or less, to approximately 400 V or more and 700 V or less, when the vehicle 1200 is running, and supplies the voltage to the inverter 1120. During regeneration, the converter 1110 reduces the input voltage output from the motor 1220 via the inverter 1120 to a direct current voltage suitable for the main battery 1210, and charges the main battery 1210. The input voltage is a direct current voltage. When the vehicle 1200 is running, the inverter 1120 converts the DC boosted by the converter 1110 into a predetermined AC and supplies it to the motor 1220, and when regenerating, it converts the AC output from the motor 1220 into DC and outputs it to the converter 1110.

[0114] As shown in FIG. 14, the converter 1110 includes a plurality of switching elements 1111, a drive circuit 1112 that controls the operation of the switching elements 1111, and a reactor 1115, and converts the input voltage by repeatedly switching the switching elements 1111 on and off. In this case, the conversion of the input voltage means stepping up or down the voltage. The switching elements 1111 are power devices such as field-effect transistors and insulated gate bipolar transistors. The reactor 1115 utilizes the properties of a coil that prevents changes in current flowing through a circuit, and has the function of smoothing changes when the current attempts to increase or decrease due to switching operations. The reactor 1115 includes the reactor 100 of the embodiment.

[0115] In addition to the converter 1110, the vehicle 1200 also includes a power supply converter 1150 connected to the main battery 1210, and an auxiliary power supply converter 1160 connected to the main battery 1210 and a sub-battery 1230 serving as a power source for the auxiliary equipment 1240, for converting the high voltage of the main battery 1210 to a low voltage. The converter 1110 typically performs DC-DC conversion, while the power supply converter 1150 and the auxiliary power supply converter 1160 perform AC-DC conversion. Some power supply converters 1150 perform DC-DC conversion. The reactors of the power supply converter 1150 and the auxiliary power supply converter 1160 may have a configuration similar to that of the reactor 100 of the embodiment, but may have a different size, shape, or the like, as appropriate. The reactor 100 of the embodiment may also be used as a converter that converts input power, and that only boosts or only bucks the voltage. [Explanation of symbols]

[0116] 100 reactor 10 coils 110 first coil portion, 120 second coil portion 121 first end, 122 second end 131,132 Terminal 1. Flat wire 1i inner circumference, 1e outer circumference 11i first inner periphery, 11e first outer periphery, 11b bent part 12i second inner periphery, 12e second outer periphery, 12b bent part 11d First displacement, 12d Second displacement 15 Space 2 turns, 20s straight section, 20c corner section 21 first turn, 22 second turn 21g, 22g gap 30 magnetic core, 31 first core, 32 second core 30i inner core, 30g gap 300 Middle core part 301 First middle core part, 302 Second middle core part 310 first end core portion, 320 second end core portion 330 first side core portion, 340 second side core portion 41, 42 holding member, 43 through hole 50 Temperature Sensor 70 Fixing material 800 bending section 810 holding portion, 811 shaft, 812 support, 813 flange 812f first page, 813f second page 820 guide portion, 821 guide groove 1100 Power Converter, 1110 Converter 1111 switching element, 1112 drive circuit 1115 Reactor, 1120 Inverter 1150 Power supply converter, 1160 Auxiliary power supply converter 1200 vehicles 1210 Main battery, 1220 Motor 1230 Sub-battery, 1240 Auxiliary equipment, 1250 Wheels, 1300 Engine Gd displacement L is the total length of the coil, L1 is the length of the first coil section, L2 is the length of the second coil section

Claims

1. A coil used in a reactor, The coil has a first coil portion and a second coil portion continuously connected to the first coil portion in the axial direction of the coil, The first coil portion includes a plurality of first turns formed by spirally winding a rectangular wire edgewise, Each of the plurality of first turns comprises: a first inner peripheral portion that constitutes an inner peripheral side of the first turn of the rectangular wire; a first outer peripheral portion that constitutes an outer peripheral side of the first turn of the rectangular wire, the first outer circumferential portion is bent so as to be inclined toward a first direction in the axial direction of the coil relative to the first inner circumferential portion, The second coil portion includes a plurality of second turns formed by spirally winding the flat wire edgewise, Each of the plurality of second turns comprises: a second inner peripheral portion that constitutes an inner peripheral side of the second turn of the rectangular wire; a second outer circumferential portion that constitutes an outer circumferential side of the second turn of the rectangular wire, the second outer circumferential portion is bent so as to be inclined toward a second direction in the axial direction of the coil relative to the second inner circumferential portion, a space for accommodating a temperature sensor is formed between the first coil portion and the second coil portion; The spacing of the space is 0.2 mm or more and 2.0 mm or less. coil.

2. The first turn has a corner portion where the rectangular wire is bent, a first displacement amount in the axial direction of the coil between the first inner circumferential portion and the first outer circumferential portion at the corner portion of the first turn being 0.1 mm or more and 1.0 mm or less; The second turn has a corner portion where the rectangular wire is bent, The coil according to claim 1 , wherein a second displacement amount in the axial direction of the coil between the second inner peripheral portion and the second outer peripheral portion at the corner of the second turn is 0.1 mm or more and 1.0 mm or less.

3. 3. The coil according to claim 1, wherein the gap between the first turns and the gap between the second turns are 0.076 mm or less.

4. The coil according to any one of claims 1 to 3; a magnetic core in which the coil is disposed; the temperature sensor for measuring the temperature of the coil; Reactor.

5. The magnetic core is an inner core portion disposed inside the coil; a gap portion provided midway in the longitudinal direction of the inner core portion, The reactor according to claim 4 , wherein the gap portion is disposed inside the space.

6. the magnetic core has an inner core portion disposed inside the coil, the inner core portion includes a resin core piece formed of a composite material molded body in which soft magnetic powder is dispersed in resin, The reactor according to claim 4 , wherein the resin core piece is disposed inside the space.

7. A reactor according to any one of claims 4 to 6, converter.

8. A converter according to claim 7, Power conversion device.

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